Part I: Regulatory Requirements for Accessible Public Rights-of-Way
Chapter 1: Overview of the Americans with Disabilities Act
Chapter 2: Title II Requirements
Part II: Best Practices in Accessible Rights-of-Way Design and Construction
Chapter 3: Pedestrian Accessibility
Title II, subpart A, of the ADA covers State and local government services, including the
design and construction of buildings and facilities and the operation of government
programs. Rulemaking authority and enforcement are the responsibility of the
Department of Justice (DOJ). However, the Department of Transportation (DOT) has
been designated to implement compliance procedures relating to transportation, including
those for highways, streets, and traffic management. The Federal Highway
Administration (FHWA) Office of Civil Rights oversees the DOT mandate in these areas.
(Title II, subpart B, which is not covered in this design guide, addresses the acquisition and manufacture of transportation vehicles and the operation of certain transportation systems. Rulemaking authority and enforcement for this section of the ADA are the responsibility of DOT and its modal administrations.)
ADA Implementing Regulations
Title II implementing regulations for subpart A were published in the Federal Register at 56 FR 144 (28 CFR Part 35) on July 26, 1991. These regulations have three parts:
Title II implementing regulations for subpart A were published in the Federal Register at 56 FR 144 (28 CFR Part 35) on July 26, 1991. These regulations have three parts:
1.2.1 The Preamble
The preamble contains a section-by-section analysis of the rule. It is a useful guidance document, providing both background and commentary on the rulemaking process and a rationale for the decisions reflected in the rule. It is a good source for examples and illustrations of key provisions, such as program access, undue burden, and technical infeasibility.
1.2.2 The Rule
The text of the DOJ title II rule contains all the requirements that apply to covered State and local government entities under title II, including many general, operational, and communication provisions, in addition to requirements for facility design, construction, and retrofit.
1.2.3 Accessibility Standards for New Construction and Alterations
Title II requires that facilities constructed or altered after January 26, 1992 be designed and constructed to be readily accessible to and usable by people who have disabilities. Work that conforms to the provisions of either the Uniform Federal Accessibility Standard (UFAS) or section 1-10 of the ADA Accessibility Guidelines (ADAAG) is deemed to comply with this requirement. State and local governments may choose to follow either standard.
With respect to street and sidewalk construction, there is little difference between the provisions of ADAAG and those of UFAS. UFAS, published in 1984 to guide Federal construction, is familiar to highway departments and State agencies as a consequence of Federal funding of highway and related construction. When ADAAG was developed in 1991, it was based on UFAS scoping and technical provisions.
This design guide is based on provisions in ADAAG, sections 1-10, published by the Access Board in 1991 and adopted by DOJ as the ADA Standard for Accessible Design for private sector (title III) facilities. DOT has also adopted ADAAG as its standard for accessible facility design (49 CFR Part 37).
The ADA Accessibility Guidelines contain requirements that apply to new construction
and alterations. Organized into five parts, ADAAG includes:
The scoping provisions may require: (1) that a certain accessible design element, such as
a curb ramp, be provided; (2) that if a certain element, such as telephone, is provided, it
must be accessible; (3) that a minimum number or percentage of several elements of a
type, such as parking spaces, be accessible; or (4) that an element conform to a technical
provision or section. A few scoping provisions permit limited exceptions to the general
application of accessibility requirements.
Technical provisions describe the characteristics of an accessible element, such as the slope of a ramp, the turning space required at a landing, or mounting heights for operating hardware. Some building elementstelephones are a good exampleare subject to several kinds of technical provisions as a result of separate scoping provisions. Some units must be installed at a height accessible to people who use wheelchairs; some must be equipped for use by people who are hard of hearing; others must incorporate a text telephone or support the connection of a portable text telephone. The technical provisions specify the accessibility required in scoping.
ADAAG scoping and technical provisions for new construction and alterations apply to work that is undertaken within the boundary of a site. Many of these provisions can also be applied to the design of pedestrian facilities in the public right-of-way, such as walks, ramps, and other circulation routes; street furniture; curb ramps, marked crossings, and islands; parking; and similar design elements.
In 1994, the Access Board proposed more specific rights-of-way guidelines as part of an interim final
rule containing special application sections for certain State and local government facilities. Section 14
of the interim rule adapted basic ADAAG 1-10 provisions for application to public rights-of-way, but was
not adopted as part of the DOJ Standard for Accessible Design. In November 1999, the Board established a
Federal advisory committee to develop final rights-of-way provisions from section 14 proposals. DOJ action
to include rights-of-way Standards in the title II regulation is expected in 2001.
This does not mean, however, that public rights-of-way are not covered by the ADA. Title II requires non-discrimination in all programs, services, and activities of public entities. The construction, alteration, or maintenance of the public rights-of-way is an activity of a public entity and is therefore subject to the nondiscrimination requirements. Although no Federal scoping or technical requirements have been established that apply specifically to public rights-of-way, both ADAAG and UFAS contain technical requirements for the construction of accessible exterior pedestrian routes that may be applied to the construction of public rights-of-way. In the absence of a specific Federal standard, public entities may also satisfy their obligation by complying with any applicable State or local law that establishes accessibility requirements for public rights-of-way that are equivalent to the level of access that would be achieved by complying with ADAAG or UFAS.
This design guide has been developed to provide uniform guidance to State and local governments on how to design and construct accessible public pedestrian facilities until such time as the Access Board, DOJ, and DOT issue final requirements.
Transportation organizations have also begun to incorporate accessibility requirements in their own guidelines
and documents of good practice. Industry organizations are considering the joint development of pedestrian
guidelines to complement the bicycle guidelines now in preparation for the American Association of State Highway
and Transportation Officials (AASHTO). Many State and local government transportation agencies have already
adopted pedestrian standards that include accessibility requirements. Several of these were based on the proposed
provisions of the Access Board's right-of-way guidelines in section 14 (now withdrawn).
Street, sidewalk, and shared-use path construction that is funded wholly or in part with Federal monies is also
subject to the Architectural Barriers Act of 1968 and the Rehabilitation Act of 1973, both of which currently
reference the accessibility standards in UFAS. DOT implementing regulations requiring curb ramps and other
accessibility features on Federal-aid highway construction covered by section 504 of the Rehabilitation Act have
recently been amended to reference ADAAG rather than UFAS.
Other Federal laws, including the Federal-aid Highway Act of 1973, the Urban Mass Transit Act of 1973, and the Transportation Equity Act for the 21st Century (TEA-21), all include accessibility objectives. Federal-aid programs are a primary funding source for pedestrian accessibility improvements; many access projects have been funded by transportation enhancement monies. TEA-21 clarified that accessibility improvements to pedestrian facilities are eligible for funding under the Surface Transportation Program. Approximately $33 billion is authorized over the six years of the program (1998-2003) for sidewalk improvements to comply with the Americans with Disabilities Act. In addition, transportation engineers are directed to consider accessible traffic signals where appropriate. The increased emphasis on pedestrian and bicycle modes in TEA-21 greatly expands both the opportunities for and obligations to achieve rights-of-way access. The ADA requires that all pedestrian projects be accessible, regardless of funding sources.
The highest degree of accessibility is required in new work, at the time when it is most cost-effective to
incorporate accessible design features. Compliance is measured against the applicable technical specifications
in the new construction standard.
Examples of new right-of-way construction include the application of municipal land development standards to new subdivisions, the extension of an existing right-of-way into newly annexed territory, and the master planning, design, and construction of a new town center.
An alteration is a change that affects (or could affect) access to or usability of a facility or a part of a facility.
If a covered entity alters an existing facility or part of a facility, the altered area must be accessible to and
usable by people who have disabilities to the maximum extent feasible.
Alterations must follow the ADA Standards for Accessible Design unless compliance is technically infeasible. Where the nature of an existing facility makes it virtually impossible to comply with all of the accessibility standards applicable to planned alterations, any altered features of the facility that can be made accessible must be made accessible.
Additionally, because alterations to existing rights-of-way offer fewer opportunities to mitigate the effects of topography and to incorporate maneuvering space and other accessibility features, accessibility guidelines include less stringent technical criteria for some conditions, such as a steeper permitted slope for a curb ramp where it may be technically infeasible to meet new construction requirements. Alterations, however, may not be undertaken that have the effect of reducing existing levels of accessibility below the requirements for new construction.
Examples of alterations in rights-of-way construction include a downtown sidewalk improvement project, a roadway realignment or widening, or the addition of a sidewalk along an existing right-of-way. Where additional right-of-way is acquired for a roadway project, it is important to consider accessible sidewalk construction, where appropriate. Such right-of-way acquisitions may also offer opportunities to improve access to adjacent sites and existing facilities.
Some ADA compliance problems, and even court cases, have arisen from differing interpretations of the term "alteration." Many highway agencies consider the removal of a wearing surface and its replacement with a new thickness of paving as merely routine maintenance-part of the long-term maintenance program for a roadway-and, therefore, not an "alteration." The ADA definition of an alteration, however, is much broader. The DOJ title II implementing regulation (see 28 CFR §35.151) defines an alteration as a change that "...affects or could affect the usability of a facility or part of a facility." In Kinney v. Yerusalim, a Federal district appeals court decision held, "if a street is to be altered to make it more usable by the general public, it must also be made more usable for those with ambulatory disabilities." If resurfacing affects the usability of a street for motor vehicles (or for pedestrians at crosswalks), curb ramps must be included where pedestrian routes cross curbs or other barriers to use. Surface projects of more limited scope, such as spot patching, thincoat sealing, reseating of disturbed curbing, restriping of existing markings in place, and similar efforts, could be considered as maintenance rather than alterations. FHWA policy states that agencies should plan to incorporate curb ramps on all resurfacing projects beyond normal maintenance where pedestrian routes exist.
The placement of benches, public telephones, or public toilets at specified locations within a developed streetscape or the addition of pedestrian signals at a street crossing should also be considered alterations requiring accessible features for those elements within the scope of the project.
Program accessibility is a provision of the ADA and DOJ title II regulations-not ADAAG, and applies to the existing
facilities and programs of a jurisdiction. It allows a range of methods to ensure that people who have disabilities
are not denied access to public programs. In many situations, an operational solution may achieve program accessibility
without the need for construction.
The concept of program accessibility has been widely misunderstood. Derived from regulations implementing the Rehabilitation Act of 1973, the idea of providing access to programs -not just to facilities-permits a broader and more flexible range of solutions to existing access problems. Subpart D (Program Accessibility) of the title II regulation begins with a general prohibition of discrimination, stating that a government may not deny the benefits of its programs, activities, and services to people with disabilities because its existing facilities are inaccessible. It goes on to require that title II entities operate their programs so that they are available to people with disabilities. In fact, existing facilities do not have to be made accessible if other methods of providing access are effective. Except for the installation of curb ramps--which are specifically required for program access-structural changes are an option of last resort. A pedestrian circulation system-sidewalks, street crossings, shared-use paths in the public right-of-way-is a program that a local government provides for its citizens. And it is the general availability of this program to people with disabilities that must be evaluated when considering the existing pedestrian environment. Full compliance with facility standards developed for new construction and alterations may not be required to achieve program access.
Program accessibility can be thought of as providing a basic level of usability. It targets high-priority access improvements-such as curb ramps-that eliminate major barriers to the use of existing facilities, so that people with disabilities are not excluded from participation. Program accessibility requires careful planning to identify those efforts that will provide the greatest access for the resources available. Non-construction approaches may include alternate accessible routings, relocating services or activities to accessible locations, or taking the service or benefit directly to the individual. Jurisdictions should consider whether such operational solutions will be supportable over the long term. For some rights-of-way elements, structural changes may be more economical.
In an existing right-of-way that is not otherwise being altered, the minimum requirement for achieving program accessibility is the installation of curb ramps at selected locations where existing pedestrian walkways cross curbs. This work must be identified in the transition plan required of public entities covered by title II.
2.3.1 Transition Plan
Where structural modifications are necessary to achieve program accessibility-as in the addition of curb ramps-the DOJ regulation requires State and local governments that employ 50 or more staff members to develop a transition plan that provides for the removal of the barriers at issue. With respect to pedestrian facilities, the DOJ regulation imposes a specific construction requirement. This requirement directs each jurisdiction to include in its transition plan a schedule for providing curb ramps where pedestrian walkways cross curbs and specifies a priority for locating them at:
DOJ's Title II Technical Assistance Manual notes that curb ramps may not be required at every existing walkway if a
basic level of access to the pedestrian network can be achieved by other means, e.g., the use of a slightly longer route.
Action items listed in a community's transition plan, including the installation of curb ramps at specified existing pedestrian walkways, were to have been completed by January 26, 1995. Entities that have not finished this work should review and update their schedules and place a high priority on accomplishing the work necessary to complete plan items and elements.
2.3.2 Fundamental Alteration and Undue Burden
The program accessibility obligation for existing facilities does not require a covered entity to take any action that it can demonstrate would result in a fundamental alteration in the nature of a service, program, or activity or in undue financial and administrative burdens. The decision that compliance would result in such alterations or burdens must be made by the head of a public entity or his or her designee after considering all resources available for use in the funding and operation of the service, program, or activity, and must be accompanied by a written statement of the reasons for reaching that conclusion. Furthermore, such a decision does not relieve the entity from obligations to take other remedial actions (to ensure that individuals with disabilities receive the benefits or services provided by the entity) that do not constitute an undue burden or fundamental alteration. See the DOJ regulation at 28 CFR §35.150(a)(3) and related preamble discussion for guidance.
2.3.3 Design Standards
Although structural changes undertaken for program accessibility must aim at meeting ADAAG technical provisions, it may not be feasible to achieve full accessibility in all elements and features in the developed right-of-way environment. For instance, reconstruction of the sidewalk area and relocation of existing features on it will not generally be necessary to achieve program accessibility at an existing intersection. If it is not possible to install a curb ramp that is fully compliant with ADAAG in an existing sidewalk, each feature of accessibility should be maximized within the constraints of site conditions at that location. Every such decision must be arrived at individually, after considering the effects of contributing factors. While a standardized approach may be possible in new construction, where finished conditions can be specified within general tolerances, designing program access solutions requires case-by-case attention to field conditions. Designers who are familiar with the rationale behind accessibility specifications will be prepared to balance possible options to achieve a usable whole.
Private sector entities covered by title III must use ADAAG scoping and technical
provisions for new construction and alterations when designing buildings, facilities, and
related site improvements. Where pedestrian routes are provided within the boundaries of
a site from parking areas, public sidewalks, or public transportation stops and building
entrances, at least one route must meet ADAAG criteria for an accessible route. In
addition, where pedestrian routes connect buildings and facilities on a common site, such
as in an office park, multibuilding complex, recreation area, shopping center, or school
campus, at least one such route must be accessible. Pedestrian elements along accessible
routestelephones, drinking fountains, kiosks, and similar facilitiesmust also meet
ADAAG requirements. ADAAG site development criteria require that on-site
connections to public streets, sidewalks, and transportation facilities must be accessible.
ADAAG (or UFAS) is also the design standard for public entities constructing individual
or multiple facilities on sites bounded by property lines or rights-of-way. The design of a
new city hall, government center, courts or correctional complex, State university
campus, municipal park, or public zoo must comply with title II site development and
Scoping and technical provisions that govern such construction can be found at: ADAAG 4.1.2 Accessible Sites and Exterior Facilities, ADAAG 4.1.3 New Construction, and ADAAG 4.1.6 Alterations.
ADAAG provisions have been developed from research that measures the responses of a wide range of people with disabilities. The features that are required in ADAAG for the accessible route on a site are, for the most part, the same features necessary to ensure the accessibility of a public sidewalk or shared-use path in the public right-of-way. For example, an abrupt 1/2-inch (13 mm) change in level is as significant a barrier to wheelchair travel on a public sidewalk as it is on an accessible route on a site.
Not all the design criteria required of an accessible route on a site, however, may be feasible in a public right-of-way. For example, it may not be possible in sloping terrain to limit the running slope of a sidewalk to 1:12 (8.33%), which is the maximum permitted for a ramp on an accessible route. Nor is it practical to propose that sloping walks be uniformly provided with handrails. Applying such standards could interfere with the normal use of pedestrian circulation facilities. Nevertheless, it is wise to plan new sidewalks to minimize running slope as much as is feasible and, where walkways are steep, to consider elements that may make them more usable, including handrails, level landings at reasonable intervals, and benches for resting.
Technical provisions for accessible features appropriate to pedestrian facilities may be found in the following sections of ADAAG:
4.2 Space Allowance and Reach Range
4.3 Accessible Route
4.4 Protruding Objects
4.5 Ground and Floor Surfaces
4.6 Parking and Passenger Loading Zones
4.7 Curb Ramps
4.15 Drinking Fountains
4.22 Toilet Facilities
4.27 Controls and Operating Mechanisms
4.29 Detectable Warnings
4.31 Public Pay Telephones
4.32 Fixed or Built-in Seating and Tables
4.34 Automated Teller Machines
Pedestrians who have mobility impairments, including those who use wheelchairs, will
benefit most from design approaches that minimize physical barriers to travel and
maneuverability. Pedestrians with cognitive and sensory impairments, particularly those
who have limited vision and those who are blind, should have access to information on
the pedestrian environment that is necessary for independent travel.
Most provisions in the standards can be applied without difficulty when new construction or alteration of streets and sidewalks, is undertaken. The DOJ Title II Technical Assistance Manual advises covered entities to apply appropriate ADAAG (or UFAS) technical provisions to the extent possible when no standards exist for particular features.
Many States have adopted these or similar standards; several require a higher degree of accessibility in public rights-of-way. DOJ technical assistance rendered in response to questions about ADA coverage of sidewalks in residential areas notes that public sidewalks are considered a program of State or local government. Where sidewalk construction is undertaken by, on behalf of, or subject to, the design standards of a public jurisdiction, it must be accessible to pedestrians who have disabilities. Public sidewalks, curb ramps, street crossings, and other pedestrian features that meet ADAAG, UFAS, or other accessible design criteria (that meet or exceed ADA accessibility requirements) in effect in a jurisdiction are deemed to comply with ADA title II requirements.
3.1.1 Construction Tolerances
The right-of-way environment is typically held to less exacting tolerances for finishes, dimensions, and other parameters than are buildings and other facilities. It is rare for a fractional dimension to have significance in highway specifications. The dimensions of accessibility, however, must be more finely measured: a difference of more than 1/4 inch (6.5 mm) in the elevation of adjacent surfaces can significantly affect the usability of a walkway; a change in slope from 1:12 (8.33%) to 1:10 (10%) may preclude the independent use of a curb ramp by some pedestrians. For this reason, it is particularly important to design and specify exterior facilities that are well within the limits established in accessibility standards.
By specifying the maximum permissible slope, an engineer may miss the opportunity to achieve a lesser and, therefore, more usable slope. Furthermore, field construction based on such a specification may fail to achieve the access that is required, leading to liability for changes that may be costly. Dimensions noted in accessibility provisions as maximum or minimum should not, therefore, be considered dimensions for design, because they represent the limits of a requirement. To be sure that field tolerances result in usable construction, notes and dimensions in construction documents should identify and incorporate expected tolerances so that a required dimension is not exceeded by the addition of a finish or a variation in construction practice. Plans that reflect such considerations also provide a better basis for decision making in the field.
Dimensions noted in accessibility guidelines have been derived from research conducted in English units. Metric equivalents currently incorporated in the guidelines do not conform to transportation industry practices. (Hard mathematical conversions are used in accessibility guidelines, while soft close equivalents based on standardly-rounded metric units are the basis for highway dimensions.) Industry conversion tables typically do not include lengths of less than 1 inch (25 mm). These conversion tables thus cannot express the difference, as provided in ADAAG, between a lip of 1/4 inch (6.5 mm), which is permitted to be vertical, and one of 1/2 inch (13mm), which must be beveled. Such differences can be important to the usability of a pedestrian route. The following conversion table has been proposed for upcoming revisions to the ADA Accessibility Guidelines:
|Metric Rounding Tolerance|
(inches x 25.4, rounded to: mm/m)
|<1/2 inch||nearest tenth of a millimeter|
|1/2 inch to <3 inches||nearest millimeter|
|3 inches to <10 feet||nearest 5 millimeters|
|10 feet to ~33 feet||nearest 10 millimeters (where conversion is less than 10 000 mm)|
|~33 feet and greater||nearest meter (where conversion equals or exceeds 10 000 mm)|
Dimensions specified in this document note the English unit first (as specified in the ADA standards), followed in parentheses by its metric equivalent (from the chart above). Although ADAAG initially (1991) specified cross slope at 1:50 (2%) maximum, site design practices in architecture and landscape architecture continue to use 1:48or the easily-figured 1/4 inch per footfor the English-unit measure. Revisions to ADAAG will recognize this practice by establishing 1:48 (2%) as the equivalent for cross slope. This manual also adopts that practice.
3.1.3 Path of Travel
On a site, the property line establishes the limits of the obligation to improve the path of travel to an altered area of a building or facility. In the public right-of-way, the path-of- travel obligation is contained within the scope and physical limits of an improvement contract or project limit. The altered area should, to the maximum extent feasible, provide an accessible connection to adjacent existing segments of the pedestrian network and related pedestrian facilities. Where necessary, corresponding modifications to adjacent areas within the project limits may be needed to ensure that grades, finishes, and surfaces will meet or match those of the alteration. This is routinely done in roadway and sidewalk construction. The Department of Justice has not interpreted the path-of-travel obligation to extend beyond the limits of an alteration project and its connections to existing improvements.
Sidewalks are walkways that parallel a street or highway within the roadway border
width. The term generally implies a separated (horizontally and/or vertically) and paved
surface. Sidewalks in the public right-of-way most commonly border and take the slope
of adjacent roadways.
Shared-use paths may also serve a pedestrian circulation/transportation function, particularly in suburban and rural rights-of-way. Where such a route is located in a public right-of-way and provides a direct pedestrian connection between neighborhoods, residential areas, schools, employment centers, and other origins and destinations, it must be accessible.
Other public pedestrian routes may parallel water or rail transportation corridors or occupy public rights-of-way in easements. Roadway shoulders may also be used by and improved for pedestrians. When used for utilitarian circulation purposes (rather than recreation, for example), pedestrian facilities are considered a transportation mode.
In urban areas, sidewalks predominate; in outlying areas and in the pedestrian transportation corridors that link them to other destinations, shared-use paths may be more common. Because each route provides a unique connection between diverse origins and destinations, such pedestrian routes, when they occupy the public right-of-way, must be designed and constructed to be accessible.
Pedestrian routes that are located within sites rather than in the public right-of-way must comply with ADAAG (or UFAS, if it is a public, Federal, or Federally assisted project). Site planners must provide at least one accessible route from public transportation stops, accessible parking, and accessible passenger loading zones, and public streets and sidewalks to the accessible building entrance they serve. At least one accessible route also must connect accessible buildings, facilities, and spaces that are on the same site.
Trails designed for recreation on sites, in parks, and in wilderness areas are included in a separate ADA rulemaking now under development by the Access Board. Additional guidelines specific to recreation uses will be proposed by the Board in future rulemakings.
This manual addresses sidewalks, walkways, and similar pedestrian transportation routes that are located within a public right-of-way. Given the importance of pedestrianism as a transportation mode and the fact that the pedestrian routes are used even when affected by rain, snow, or ice, providing more than the minimum of access features is strongly encouraged.
The utilitarian transportation function of sidewalks also suggests a high priority for accessibility. Ideally, the sidewalk network that makes up a public pedestrian circulation system should permit passage to every address and pedestrian feature on or along every pedestrian route.
The pedestrian provisions in the Green Book of the American Association of State Highway and Transportation Officials (AASHTO) recommend sidewalk construction for most locations. New directives in Federal transportation legislation support the provision of pedestrian and bicycling elements whenever roadway work is undertaken. However, ADA implementing regulations do not require paved walks or curb ramps where pedestrian routes are not otherwise provided. When a pedestrian route is constructed, however, it must be accessible.
Walkway width recommendations in current transportation industry guidelines generally
exceed the 36-inch (915-mm) minimum needed for accessible travel. The Institute of
Transportation Engineers (ITE), in its 1998 recommended practice publication, Design
and Safety of Pedestrian Facilities, recommends planning sidewalks that are a minimum
of 5 feet wide (1525 mm) with a planting strip of 2 feet (610 mm) on local streets and in
residential and commercial areas. Sidewalks in central business districts should be wide
enough to meet level-of-service criteria. AASHTOs Green Book recommends a
minimum paved width of 3 metersapproximately 10 feetfor shared-use paths. The
accessible widths in UFAS and ADAAG are minimums for passage, not sidewalk width
recommendations (SEE FIGURE 1).
Because wheelchairs, like other wheeled vehicles, do not track within the same path when turning, additional length and width are necessary at turns. And because the length of a wheelchair space48 inches (1220 mm)exceeds its width of 30 inches (760 mm), extra walkway width is necessary to turn and operate an entrance door, to approach and activate a pedestrian crossing signal button, or to enter or leave a curb ramp (SEE FIGURE 1). Passing space for two wheelchairs can be provided in a space that is 60 inches (1525 mm) wide, which is usually available at a corner, a driveway, or a building entrance (ADAAG requires passing spaces to be located at reasonable intervals, not to exceed 200 feet/61m, along accessible routes). A circle 60 inches (1525 mm) in diameter will minimally accommodate a full reverse in direction.
Narrow sidewalks immediately adjacent to street curbs provide little margin for maneuvering, particularly in crowds when line of sight is limited or when water, snow, or ice make control less precise. A moment's inattention or a blocked view may well result in a fall if a crutch tip or wheel drops off a sidewalk edge or into a planting recess. Wider walkways minimize the hazards presented by such dropoffs.
Some pedestrians who use crutches need as much as 42 inches (1065 mm) in width to achieve a comfortable gait. An individual traveling with a service animal or sighted guide will use a minimum of 48 inches (1220 mm) of width for easy passage. Sidewalks that are at least 60 inches (1525 mm) wide allow pedestrians to travel comfortably side-by- side and are the minimum convenient width for turning or passing.
Reconstruction of an existing intersection or roadway may make it possible to reapportion the right-of-way width between street, sidewalk, and landscaping elements or even to modify the street elevation or curbface height to improve access (SEE FIGURES 2 AND 3). Where sidewalk width is inadequate or sidewalk cross slope is excessive, the adjacent street may have sufficient width to borrow for sidewalk expansion. Some traffic- calming measures (bulbouts and curb extensions, for example) can also produce extra sidewalk width (SEE FIGURE 4). Increased walkway width can better accommodate curb ramps and landings at pedestrian crossings. Where the full width of a sidewalk cannot be altered to meet cross slope requirements, it may be possible to blend in a complying passageway within it.
3.2.2 Running Slope
On a new site, a knowledgeable designer can often manipulate cut and fill, entrance
location, and approach direction and length to limit walkway running slope to 1:20 (5%),
adding, where necessary, ramped segments with handrails and landings at or below the
1:12 (8.33%) slope specified in accessibility standards for ramps. These slopes will not
be consistently possible to achieve along public sidewalks and shared-use paths, where
running slope is tied to roadway gradient and underlying terrain. Nevertheless, running
slope should be kept to the minimum feasible consistent with these factors. Artificial
slopes should not be added as landscaping features, nor should meandering walkways
that add significantly to the travel distance be permitted on a primary circulation route.
Level runouts can provide access to entrances located along sloping sidewalks (SEE FIGURE 6). Alternatively, a wider sidewalk can accommodate the blending room necessary for a transition to the level landing required at entrances. Parallel ramps may also be used to provide access to existing raised entrances constructed originally with steps (SEE FIGURES 7 AND 8). Stairs may connect diverging sidewalk levels, as long as a stair-free route is also available.
3.2.3 Cross Slope
Excessive cross slope is a major barrier to travel along sidewalks for pedestrians who use wheelchairs and scooters, pedestrians who use walkers and crutches, pedestrians who have braces or lower-limb prostheses, and those with gait, balance, and stamina impairments. Energy that might otherwise be used in forward travel must be expended to resist the perpendicular force of a cross slope along a travel route. Cross slopes that exceed 1:48 (2%) significantly impede forward progress on an uphill slope and compromise control and balance in downhill travel and on turns. Because the cross slope of a sidewalk is typically toward the roadway, the pedestrian who loses traction or balance will be directed toward the street. In wet or freezing weather, travel across a slope always carries the threat of sliding into the roadway (SEE FIGURE 8).
Pedestrians who use crutches are particularly susceptible to cross slope when they are traveling downhill. Children, including children with disabilities and those using bicycles and other wheeled toys, are primary users of sidewalks in residential areas and are significantly less able to compensate for cross slope than adults.
Driveway aprons in residential subdivisions where narrow sidewalks are immediately adjacent to the curb are the most frequently encountered example of excessive cross slope along a pedestrian route. A level area with minimal cross slope is necessary for accessible passage across a driveway. Driveway aprons that are constructed like ramps, with steep, short side flares, can render a section of sidewalk impassable, especially when encountered in series, as in residential neighborhoods. Compound cross slopes, such as those that occur at the flares of a driveway apron or curb ramp, may cause tipping and falling if one wheel of a chair loses contact with the ground or the tip of a walker or crutch cannot rest on a level area (SEE FIGURE 9). A walker must have a flat plane to rest on if it is to provide adequate support. Wheelchair users whose upper trunk mobility is limited can be thrown from their seats by differentials in cross slope occurring over a small distance. Manual chairs, although more maneuverable than battery-heavy power chairs, are much more likely to tip on compound slopes. When this happens, it is difficult to recover control, direction, and traction.
Several design approaches are possible to achieve a complying apron, including a retrofit treatment for existing driveways that ensures a passageway across the opening that does not exceed cross slope limits (SEE FIGURES 10 AND 11).
Walkways that curve tightly while sloping are also problematic, requiring constant stroke or gait adjustment. Sidewalk intersections in hilly terrain should be planned to avoid excessive cross slope toward the street. Where sidewalks of excessive cross slope are being reconstructed, it may be possibleif there is sufficient widthto provide a 36- inch-wide (915-mm) continuous routing with a complying cross slope within the overall sidewalk width, blending adjacent surfaces to meet it.
Where accessible sidewalks intersect at a corner, a level landing (1:48 or 2% in each travel direction) should result. Limiting cross slope requires careful attention to walkway design and construction to maintain positive drainage. Because the range-of-finish tolerance is greater in the right-of-way environment than in building and facility construction, it is particularly important that contractors work to the 1:48 (2%) maximum to ensure a usable result.
Sidewalks and shared-use paths should meet the ...stable, firm, and slip-resistant...
criteria established in accessibility standards. The Access Board's Technical Assistance
Bulletin #4: Surfaces contains additional information on the performance requirements
for walking surfaces on an accessible route.
In extremes of climate, where wet or freezing conditions occur frequently, surface water must be carefully controlled and maintenance must be emphasized in both the vehicular and pedestrian way. Salted or broom-finish concrete provides good slip resistance; a broom finish is also useful in channeling runoff across a walkway.
Where unit pavers are installed, it may be difficult to achieve positive drainage within the 1:48 (2%) cross slope recommended for sidewalks and shared use paths. For these surfaces, permeable or open joints may be necessary to control ponding. Some specialty pavings are not suitable for sidewalks, although they may have applications along walkwaysor portions of walkways--not required to be accessible. Split-face stone units, cobblestones, and similar irregular surfaces are not easily traversed by pedestrians who have mobility impairments and may catch a dragging foot or trigger a painful spasm in response to repeated jarring in some wheelchair users. Nevertheless, some textured walking surfaces can provide useful cues to pedestrians who are blind when such materials are used as borders and edges of walkways and street crossings. Standardization and consistency in use are important for effective communication of right-of-way information. The wide range of surface textures commonly encountered on sites and public sidewalks, however, makes it difficult for blind pedestrians to derive a particular meaning from a difference in a commonly-used pattern or material. Exposed aggregate finishes have been found to be slippery when wet and are not recommended for sloping surfaces. Incised or imprinted patterns may not be detectable underfoot or to a cane. Research has shown that the truncated dome specification in ADAAG 4.29.2 is highly detectable to blind pedestrians and can be used effectively to indicate the location of a crosswalk or to indicate the division between a walkway and vehicular way, particularly where there is no distinguishable curb. Placement is critical: materials should be installed on the pedestrian walkway or curb ramp immediately adjacent to the street. (See 3.5.1 Street/Sidewalk Detectability for additional discussion).
Other surface features that affect accessibility include gratings and similar fittings that have horizontal openings or gaps that exceed 1/2 inch (13 mm) in the direction of travel. Such gaps can capture the small front wheel of a wheelchair or the end of a crutch, suddenly stopping forward progress and possibly leading to a tip or fall. Additionally, the frame angles in which access covers and gratings are set often result in significant gaps when installed in a sidewalk.
Metal gratings are of particular concern to pedestrians who use walking aids. When wet, the grids can be extremely slippery, and the elongated openings can become a sliding track for the tip of a crutch or cane. Slip-resistant finishes or nonmetallic materials are available at additional cost for installations where the location or extent of exposed gratings may pose a problem for pedestrians, such as on pedestrian bridges and overpasses. Where possible, gratings and similar sidewalk fittings should be located off the travel path. Note, however, that tree gratings--unless part of the pedestrian circulation route need not meet surfacing provisions.
Flangeway gaps at rail crossings, particularly where light rail lines are integrated into a street or a pedestrian mall, are a growing accessibility concern. Where the accessible route in a transit station must cross a track, accessibility standards permit the inner flangeway gap at the rail to be no more than 2-1/2 inches (63 mm). If the gaps are larger than that, an over- or underpass is required. Even this dimension, however, may be problematic. There have been numerous reports from pedestrians who use wheelchairs describing circumstances in which the small front wheels of a manual chair dropped into a flangeway gap and could not be extricated. Even the larger wheels of a power chair can swivel and drop sideways into a gap of this dimension, especially if the rail is raised above the surrounding surface. Rail lines that carry freight cars may need as much as a 4- inch (100 mm) flangeway to avoid train derailings. Flangeway fillers that are currently available do not hold up at the weights and speeds of travel common on freight systems, but may be acceptable on lines that serve only light rail vehicles.
Sidewalk surfaces that have settled or heaved over time can be a significant barrier for pedestrians. Surfaces that are smooth and rollable when newly installed may not stay that way, particularly where masonry units are installed without an adequate subbase. Knowledgeable design, wise material selection, good construction practices, and regular maintenance procedures can help ensure that differences in level between adjacent units do not exceed the limits of usability. Surface provisions for an accessible route limit allowable vertical differences in level between abutting surfaces to no more than 1/4 inch (6.5 mm); if bevelled at 1:2, a 1/2-inch (13-mm) difference in elevation is permitted.
Although it may not be feasible to meet new construction criteria consistently along older sidewalks, agencies and entities responsible for sidewalks should note that the DOJ regulation includes requirements for the maintenance of accessible features. Public works departments should respond quickly to citizen reports of damaged surfaces along high- priority routes, so that pedestrians with mobility impairments do not have to seek alternate routes. A maintenance program targeted to heavily used routes and, where necessary, a snow removal program that includes clearing curb ramps at street crossings will minimize delay and inconvenience for pedestrians with disabilities.
Maintenance of pedestrian routes should also be considered a program of an entity covered by title II. Where abutters or owners of adjacent property are charged with responsibility to fund repairs or improvements or to clear snow from sidewalks, municipalities should consider how to ensure the accessibility of those routes.
3.2.5 Pedestrian Envelope
The passage along or within a sidewalk or shared-use path should be clear of obstructions
underfoot, overhead, or in between. Objects that protrude over a circulation route above a
height of 27 inches (685 mm) are not detectable by cane.
Objects that encroach on a travel path can be a significant hazard for pedestrians who are blind (SEE FIGURES 12 and 13). Elements below 80 inches (2030 mm) that overhang a sidewalk or shared-use path, such as awnings, banners, signs, and tree branches, and items that protrude into the sidewalk above a height of 27 inches (685 mm), including wall-mounted telephones, projecting signal boxes, and similar impediments, often are not detected by blind pedestrians who use a long cane to travel independently. In contrast, street furnishings with a leading edge below 27 inches (685 mm)benches, bus stop enclosures, sign poles, and signal and lighting standardscan be more easily identified and avoided.
Wall-mounted elements at or above 27 inches (685 mm) should be limited to a 4-inch (100-mm) projection into any travel route. Although post-mounted items are permitted to overhang a support by 12 inches (305 mm) because the post itself should be detectable at its base, many pedestrians who are blind question the rationale for this provision. These pedestrians assert that post-mounted items are no more detectable than those that are wall-mounted and, thus, should be limited to the same 4-inch (100-mm) dimension.
A straightforward and predictable routing along a sidewalk, where equipment, street furniture, landscaping, and utilities are grouped together in a zone along the curb, will facilitate travel by pedestrians who have vision impairments. Note, however, that large open areas that do not have detectable landmarks, traffic sounds, or vertical facades that reflect sound may not offer sufficient cues for orientation and wayfinding. Where a corner lot is occupied by a park, parking lot, or building setback, it may be helpful to provide a raised curb or a grass or planted edge as a shoreline for cane travelers.
3.3.1 Continuous-Flow Intersections
Although many traffic-calming measures now gaining acceptance in the United States will benefit pedestrians with disabilities, those who are blind or have low vision are concerned about the lack of crossing opportunities at roundabouts and unsignalized traffic circles. Visual observation is the only way to identify and select a gap for crossing at these locations. Analyzing traffic sounds is not a technique that can be effectively applied to crossings at these and other continuous-flow intersections, including many free right turn locations. Where traffic volume or speed is high, pedestrians with vision impairments (as well as children, pedestrians who have cognitive disabilities, and those who travel slowly) must often choose an alternate route that avoids such intersections. Although State white cane laws require motorists to yield the right-of-way to pedestrians crossing with white canes or service dogs, anecdotal information suggests that this rarely occurs and is not easy to enforce. The American Council of the Blind (ACB) and the Association for the Education and Rehabilitation of the Blind and Visually-Impaired (AER) have initiated research to determine how to ensure access to these types of intersections.
At unsignalized street crossings, including roundabouts, pedestrians who use wheelchairs are at a higher risk of being struck by moving vehicles because they are not easily visible to motorists, particularly where they must cross in front of more than one lane of traffic going in the same direction.
3.3.2 Geometric Design
Curb radii have gradually increased over the last several decades to accommodate the longer wheelbases of trucks and buses. This has greatly reduced the sidewalk area available for installation of signs, signal standards, control boxes, and other roadway appurtenances. Pedestrian platooning space at street corners has also been reduced. Where curb radii are large, pedestrians may be waiting in an area that lies outside a drivers field of vision.
Drivers, who are able to turn at higher speeds at these intersections, also have the advantage of time and momentum over the pedestrian waiting to cross and often fail to yield the right-of-way. Street crossings are longer where radii are large, and pedestrians who do not start at the beginning of a WALK cycle may not be able to complete a crossing in the allotted time. Those who travel more slowly or must wait to start until they can confirm the start of the pedestrian interval may be discouraged from attempting to cross at such intersections.
Stop lines, advanced to allow maximum storage space for vehicles awaiting a signal phase, give turning vehicles a significant edge over pedestrians when a light cycle changes; this encourages driver intimidation of pedestrians when turning. Cars waiting to turn right on red often block curb ramp and crosswalk access from the street or sidewalk. Pedestrians with vision impairments, whose cues to cross come from the sounds of parallel traffic, may not be able to detect or distinguish separate WALK cycles if turning vehicles regularly advance into the crosswalk, masking other cues. A delayed right turn may be helpful in such circumstances.
Smaller curb radii have traffic-calming effects, slowing driver speed at turns and giving pedestrians the opportunity to begin a crossing before the vehicle turns. The larger pedestrian platooning space at corners keeps pedestrians within a drivers field of view and shortens street-crossing distances and times, a benefit to both drivers and pedestrians (SEE FIGURE 14). For pedestrians who have vision impairments, the intersection with a smaller curb radius provides a more audible distinction between perpendicular and parallel traffic flows.
The curb ramp is the basic unit of accessibility in a pedestrian circulation network. Even
on steep sites, pedestrians using motorized wheelchairs or being assisted in traveling can
use curb ramps, and a connection to the street crossing should be available if there is a
Curb ramps are the only item of right-of-way construction specifically required in the DOJ title II regulation (see 35 CFR §35.150(c)(2) for existing facilities and §35.151(e) for new construction and alterations). Where new sidewalks or streets are constructed or existing pedestrian or vehicular ways are altered, curb ramps or other sloped areas must be provided at intersections with curbs or other barriers to use. Under program accessibility in existing facilities, the regulation also requires title II entities to install curb ramps along existing pedestrian routes that are not otherwise being altered to provide the benefits of public sidewalks to people who have mobility impairments. Many jurisdictions consider resident requests in establishing priorities for new sidewalks and identifying locations where curb ramps are required. DOJ title II regulations require that public entities give priority to providing curb ramps at walkways serving State and local government offices and facilities, transportation, places of public accommodation, and employees, followed by walkways serving other areas.
3.4.1 Types of Curb Ramps (SEE FIGURES 15, 16, 17, 18)
A curb ramp assembly should include top and bottom landings, the ramp run itself, and
an edge treatment, but curb ramps need not be provided with handrails. Three basic curb
ramp types are described in accessibility standards:
There are many variations of these curb ramp types. In addition, most public works plans
add several other curb ramp types, including the following:
3.4.2 Curb Ramp Usability Considerations
Sidewalk designers who understand the rationale behind accessibility criteria will be better prepared to evaluate the relative merits of curb ramp type, placement, landing width, slope, and cross slope when designing curb ramps along existing developed streetscapes (SEE FIGURE 19).
A pedestrian with a mobility impairment may be using a sport or standard manual chair, a three-wheeled power scooter with a front tiller, a standard power chair, or a large custom model capable of many seating adjustments. Each requires different features of a curb ramp for maximum usability, and performance differs in going up and down the ramp.
Large, heavy, power-driven wheelchairs cannot accomplish fine maneuvers in tight spaces, but they can be more stable on irregular exterior surfaces and can traverse a steep slope with little difficulty--as long as the power supply is available. Small, lightweight, manual chairs can maneuver tightly but are very unstable on cross slopes and are easily tipped backwards where ramp slopes are extreme. Such chairs are more versatile inside, however, particularly in older buildings where accessibility is limited and maneuvering space is at a premium, as in toilet rooms, on elevators, and at doors. Some three-wheeled power scooters with control tillers have large turning radii because of their longer wheelbases and are unstable on compound slopes because of their higher seats and narrow width.
For stability, it is important to approach the base or toe of the ramp straight on when ascending. Most manual chair users will take a run at an up-ramp to take advantage of forward momentum. To provide a straight shot to the top from the base at the street, the curb ramp needs to be perpendicular to the curb it cuts, so that both sides of the ramp are the same length (SEE FIGURE 20). If the curb ramp is skewed, with one side shorter than the other, it will be necessary to turn while ascendinga more difficult and taxing maneuveror enter the ramp at an angle to the change in slope, which affects balance and compromises control. When all four wheels of a wheelchair or scooter are not in contact with the rolling surface, some of the maneuverability necessary to deal with surface irregularities and upslopeand the control necessary to manage a downslope are lost. Because the downhill slope of a ramp usually ends in the street, a loss of control may have serious safety effects.
The selection of curb ramp type is generally a function of available sidewalk width (SEE FIGURE 21). In new construction, a 6-inch (150-mm) curb height, when combined with the 1:48 (2%) cross slope of the sidewalk, will require a sidewalk width of almost 12 feet (3600 mm) to incorporate a perpendicular ramp at a slope of 1:12 (8.33%) and a top landing that is 48 inches (1220 mm) long.
Designers can often manipulate curb height for a short distance at corners to minimize the sidewalk width necessary to accommodate the desired type of ramp (SEE FIGURE 22). It is also possible to combine types by absorbing part of the elevation change within the run of the sidewalk, thus allowing the perpendicular curb ramp to the street to be a shorter run, as in a combined curb ramp, which may be advantageous in replacing existing ramps that lack landings (SEE FIGURE 23).
Other variables include the slope of curb ramp side flares, the width of a top landing, and the rise of the ramp itself, which may be significantly lessened by extending the ramp through the width of the gutter or altering the design curb height at the intersection.
3.4.3 Curb Ramp Location
As the curb radius increases and the area of the pedestrian corner decreases, there is less sidewalk space available for the installation of curb ramps. In many existing locations, only a single diagonal curb ramp can be contained within the width of the pedestrian crosswalks at the curb. Where existing sidewalks are being retrofitted with curb ramps, it may be impossible to install paired ramps because of the location of existing drainage and sidewalk appurtenances.
Good intersection design practice suggests that all pedestrians enter a crosswalk at the same point (SEE FIGURE 24). Diagonal curb ramps that require pedestrians who use wheelchairs to follow a different route than other pedestrians, where they may not be expected by or may be less visible to a driver, increase the potential for pedestrian- vehicular conflict (SEE FIGURE 25). This is a particular problem with turning vehicles, since a driver may not check for pedestrians entering the crosswalk from non-standard locations.
An apex curb ramp must accommodate wheelchair travel to either of the two perpendicular crossing directions. Those on corners with small radii--less than 20 feet (6 m)--expose wheelchair users to moving traffic at the foot of the ramp (SEE FIGURE 26).
Although current standards for diagonal curb ramps on sites require a 24-inch (610 mm) segment of straight curbing adjacent to the flares and within the marked crossing, this is rarely observed in the public right-of-way. This condition cannot be achieved with large curb radii without depressing the entire sidewalk corner, a construction that is problematic for pedestrians who have vision impairments. This requirement was instituted after comments by blind pedestrians that single (diagonal) curb ramps constructed at the apex of a curb return made it difficult to extract directional cues to a crossing. Research on how blind pedestrians make street crossings appears to support this concern. However, orientation and mobility specialistsprofessionals who teach travel skills to newly blind people and to children who are blindnote that curb ramps are no longer taught as indicators of crossing alignment, although they are one of a group of cues that may be useful in wayfinding by pedestrians who are blind. A diagonal curb ramp does not offer a pedestrian with a vision impairment as much information about an intersection as paired ramps at corners do, particularly with respect to the location of the crosswalk.
For these reasons, diagonal curb ramps are discouraged in new construction. In alterations, they should be considered a less desirable alternative if paired curb ramps can be installed.
3.4.4 Running Slope
Curb ramp design requires a balance of run length and slope. Accessibility standards set
the maximum slope of a new curb ramp at 1:12 (8.33%) to provide maximum usability
for the widest range of people who have mobility impairments. Some pedestrians who
use wheelchairs can travel up short runs of steeper slope if the tipping angle of the chair
is not exceeded (SEE FIGURE 27). Others will choose to travel with assistance on
In existing developed rights-of-way, it may be necessary to install a steeper ramp to provide access to street crossings. In an alteration, slopes as steep as 1:10 (10%) are permitted for the distance of a 6-inch (150-mm) rise if it is not technically feasible to provide a ramp at 1:12 (8.33%). For a 3-inch (75-mm) rise, the maximum slope may be as steep as 1:8 (12.5%) where necessary. (In historic facilities, a 1:6 (16.67%) ramp with a maximum run of 24 inches (610 mm) is permitted if a lesser slope is infeasible and if the historic significance of the facility would be threatened or destroyed through the use of complying ramps).
In developed areas with existing sidewalks at steep running slopes, a switchback curb ramp serving the perpendicular crossing may provide a more usable connection to the street.
3.4.5 Cross Slope
Excessive cross slopes on curb ramps can make them unusable by most pedestrians with mobility impairments. The front casters of a wheelchair impart a downhill turning tendency when a cross slope is encountered. Counteracting this unwanted cross force requires manual or battery energy that is then not available for forward travel. Under slippery surface conditions, a loss of control or overturning can result. Such incidents usually end in the street. If a cross slope is extreme, scooters and power chairs with high centers of gravity risk tipping; sideways tips and falls are more common in power chairs and scooters, which are more frequently the aid of choice for outdoor travel. Ambulatory pedestrians who have gait impairments and those who use walking aids will have difficulty maintaining balance and continuing forward travel on curb ramps with excessive cross slope.
Curb ramp cross slope in new construction should not exceed 1:48 (2%). Where street crossings are planned at midblock or at T-intersections on sloping roadways, careful engineering is required to blend curb ramp, landing, and crosswalk at the vehicular way. In alterations, it may be necessary to accept a steeper cross slope because of the difficulty and cost of correction.
At the foot of a curb ramp, a flush connection to a moderate gutter counterslopeno
more than 1:20 (5%) for a wheelbase distance (approximately 24 inches/610 mm) from
the curbis necessary. This ensures that a wheelchair will not suddenly stop when the
front wheels or footrest are caught by an opposing upslope, propelling the pedestrian
forward and, perhaps, out of the seat, often with considerable force. In fact, some
wheelchair users add seatbelts as insurance against just such conditions. Where there is a
rapid transition from downhill to uphill slope over a short distance, a wheelchair may also
get hung up between the front casters and rear anti-tip bars, leaving the drive wheels
spinning uselessly off the ground (SEE FIGURE 27).
It is particularly important that the transition from the ramp to the street be flush, without a lip or other difference in level. Most wheelchairs are propelled by rear drive wheels; the smaller front wheels swivel freely. When these casters hit a raised lip, they swivel sideways and stop (SEE FIGURE 28). Experts can pop a wheelie in a manual chair to overcome such barriers, but many other wheelchair users will not attempt such a risky maneuver. Power chair users may have to retreat--possibly into the street--and try the slope again at greater speed.
Some pedestrians who use wheelchairs will take a run at the upslope of a curb ramp to take advantage of forward momentum. Even a small lip at the gutter edge will interrupt this progress. A substantial lip will cause many wheelchairs to stop abruptly enough to dislodge the user. On a downslope, a lip can cause the front wheels to drop suddenly, pitching the pedestrian forward and into the street (SEE FIGURES 29 AND 30). In new construction, it is possible to design gutter flow and collection so that water does not pond at the foot of a curb ramp; in alterations, it may be possible to relocate ponding away from the ramp to a less critical location by projecting the toe of the curb ramp through the gutter.
The effect of standard surface drainage design on curb ramp usability has not yet been resolved in street engineering practices. Many features developed to manage water flow- -gutter slope, lips, gratings--are inimical to accessibility. Water rises in the toe of a curb ramp (or driveway apron) and may even freeze; even a small lip may make a ramp difficult or unsafe to use; gratings can trap wheels or walking aids. Curbside hydraulic design needs to be re-engineered to address these issues effectively.
Because the side flares of a standard perpendicular curb ramp will exceed the permitted 1:48 (2%) cross slope, an accessible route cannot include travel across a flare. Flared sides are limited in their slope so that they are not a tripping hazard for pedestrians who walk across them. They are not intended for use by pedestrians in wheelchairs, who make a turn into or out of a curb ramp on the landing required at the top. Flares are not required where the edges of a curb ramp are protected by landscaping or by such appurtenances as signal standards, controller boxes, or other barriers to travel across-- rather than up or down--a curb ramp (SEE FIGURE 31).
Level landings at the tops of curb ramps make it possible to change direction after
completing the ascent, rather than during the rise, and to avoid traveling across the
compound slope of a side flare when using the sidewalk rather than the curb ramp (SEE
FIGURE 32). Top landings also provide a level area that allows pedestrians to bypass
curb ramps entirely when traveling around a corner or to a street crossing that is in line
with the direction of travel.
A landing length of at least 48 inches (1220 mm), the length of an occupied wheelchair; is required at perpendicular curb ramps in new construction; 60 inches (1525 mm) is preferred. In alterations in more constrained rights-of-way, 36 inches (915 mm) may be adequate if toe room is available beyond the sidewalk. Landing length is measured in the direction of travel to and from the ramp.
On parallel ramps, landings must be at least 60 inches (1525 mm) long to avoid trapping the footrest of a wheelchair between opposing upslopes. Landings are considered level when their slopes in the two perpendicular directions of travel do not exceed 1:48 (2%).
Where no turn is required on a landing to enter or leave a curb ramp, the slope of the landing in the direction of travel may be 1:20 (5%). These conditions are commonly found in the crosswalk at the foot of a curb ramp. Where a diagonal curb ramp is installed so that pedestrians using wheelchairs must make a turn to enter the crosswalk, the bottom landing in the street should be level (that is, with no more than a 1:48 [2%] running and cross slope) for a distance of at least 48 inches (1220 mm) to provide maneuvering space. This area should fall within the confines of the crosswalk markings and should not expose pedestrians entering one crossing to vehicles travelling in the opposing direction.
3.4.8 Alternatives to Curb Ramps
Curb ramps are not the only way to make a street crossing accessible to pedestrians who use wheelchairs. Some pedestrian districts have installed raised crosswalks at intersections, requiring vehicles, rather than pedestrians, to ramp up and down (SEE FIGURE 33). Raised crossings (also known as speed tables) are now being designed as traffic-calming measures in many communities and can be useful in making narrow sidewalks accessible without the installation of curb ramps. Care must be taken to ease the vehicle ramp so that drivers with disabilities are not affected by a sudden jolt.
Uncurbed transitions between sidewalk and street make it difficult for pedestrians with vision impairments to identify the boundary between pedestrian and vehicular areas. Detectable warning surfaces (see ADAAG 4.29.2) placed at the edge of the walkway adjacent to the street can provide information about the presence of a crosswalk, replacing the cues once provided by raised curbs. Audible locator tones installed in pedestrian pushbuttons may also be useful in identifying intersections.
Many older cities and towns have sidewalks raised well above street level, with two or three steps at corners to connect to the street crossing. If there is sufficient walkway width to do so, it is possible to ramp a portion of the sidewalk down to the intersection using design criteria for ramps. Although handrails would not usually be provided at curb ramps, they should be installed on longer ramp runs where the elevation change exceeds typical curb height (SEE FIGURE 34).
Pedestrians who have vision and mobility impairments and cognitive disabilities are
increasingly at a disadvantage when they leave the sidewalk to cross the street. The lack
of useful information at intersections for blind pedestrians and those who have low vision
is a particular impediment to independent travel.
Computerization of traffic operations has allowed substantial increases in traffic volume
by designing for maximum vehicle time and space utilization, usually at the expense of
pedestrians. The simple, straightforward street/sidewalk grid, with its 90-degree
intersections controlled by fixed-time signaling, has been replaced by free lanes for
turning traffic, multiphased crossings, and right turns on red for vehicles. In some
configurations, traffic never stops. As complex traffic operations become the norm,
pedestrians have had to rely on speed and vision to negotiate intersections.
3.5.1 Street/Sidewalk Detectability
Sidewalks that ramp gradually down to a street crossing give little notice of the change
from pedestrian to vehicular way for pedestrians who are blind. The blended or depressed
corners and wide diagonal curb ramps popular in downtown improvement projects a
decade ago were found to be difficult to detect; pedestrians with vision impairments were
not able to identify the boundary between the sidewalk and the street. Raised crosswalks
that continue across a street at curb height do not provide curbline cues for pedestrians
with vision impairments. Narrower curb ramps with more steeply sloping side flares or
returned curbing are, however, easily identified using a long cane. Research supports the
need for additional cues for blind pedestrians at locations where standard indicators, such
as curbs or detectable curb ramp slopes, are absent.
Where ramp slopes fall below detectable limits (in California, ramp slopes of 1:15/6.67%
or less), a tactile feature underfootsuch as the truncated domes of the ADAAG
detectable warning specificationcan provide a confirming cue (SEE FIGURE 35), if
their meaning is known. However, there has been controversy about the application of
detectable warnings on exterior sloped areas. A joint rulemaking by the Access Board,
DOJ, and DOT has temporarily suspended the ADAAG requirement for detectable
warnings on curb ramps, at reflecting pools, and at hazardous vehicular areas until July
2001 to determine if such surfaces pose problems for pedestrians who have mobility
impairments (see Technical Assistance Bulletin #1: Detectable Warnings). Research
completed for the Access Board in 1994 did not reveal any safety problems with
detectable warnings installed on pedestrian surfaces. However, pedestrians with mobility
impairments have expressed concern over their use on the slopes of curb ramps and
transportation agencies anticipate problems with snow removal.
Over 30 U.S. firms currently manufacture the distinctive truncated dome surfacing that signals an approaching curbline underfoot. This tactile treatment is required at transit platform edges in the United States and is widely installed on curb ramps and at intersections in Japan, Australia, and Great Britain. Germany, France, and Belgium have begun pilot tests. An international standard is under development. Several U.S. cities have continued to install detectable warnings on new and altered curb ramps without reported problems. Engineers have suggested that the rows of flat-topped domes (less than 1/4 in/6.5 mm high) be oriented to provide a clear track for wheelchair passage over a curb ramp. Some pedestrians who are blind recommend a width of only 24 inches (610 mm)--as is required along transit platforms--for adequate detectability, which may be less objectionable to wheelchair users.
Pedestrians who have low vision will benefit from the marking of curb ramp surfaces with a contrasting color, texture, pattern, or other finish; many would choose to avoid a curb ramp, if possible. Wheelchair users have also reported the effectiveness of a contrast in curb ramp surface in identifying where an opposing curb ramp meets the street, allowing pedestrians to travel quickly and directly across the roadway to an up-ramp. Where concrete paints or stains are used, care must be taken to ensure a slip-resistant surface, particularly when wet.
Transportation industry research on color, contrast, and visibility for roadway markings has not included subjects who have low or otherwise impaired vision. Until testing can be undertaken to determine the effectiveness of standard pedestrian markings for these users, the criteria in the Manual on Uniform Traffic Control Devices (MUTCD) are a useful guide. Several states require a particular color to mark accessible features; however, there are no specific color requirements in ADAAG or UFAS.
3.5.2 Accessible Pedestrian Signals (APS)
Pedestrians who are blind use audible and tactile cues in independent travel. At intersections with fixed-time signal phasing and consistent traffic flow, traffic light changes will be reflected in parallel or perpendicular traffic surges. The sounds of these surges are used by blind pedestrians to identify appropriate crossing intervals.
Intersections that have actuated signal timings, complex traffic patterns, or intermittent or sporadic traffic volumes may pose problems for pedestrians who have vision impairments. At these intersections, the signals for automobile and pedestrian traffic do not automatically correspond. Frequently, a separate WALK signal and phase is provided for pedestrians in response to a pushbutton. At this type of crossing (as well as at several other types, including midblock crossings where there is no parallel flow to rely on), an accessible pedestrian signal (APS) may be desirable to provide blind and low-vision pedestrians with an equivalent to the visual signal provided for other pedestrians.
Although audible crossing indicators have been available for over 20 years, they have not been well received by traffic planners in the United States. This is probably attributable to two factors: One is noise pollution and consequent community opposition; the other is disagreement among blind people on the need for audible pedestrian signals.
TEA-21 amended Federal transportation law to include a directive that audible pedestrian signals be considered where appropriate for pedestrian safety. However, accessibility standards do not yet include scoping or technical specifications for audible crossing signals or other means of communicating visible information to pedestrians who have vision impairments. A standard has been proposed for inclusion in the next edition (2000) of the Manual of Uniform Traffic Control Devices.
3.5.3 Types of Accessible Pedestrian Signals
The Access Board has published Accessible Pedestrian Signals (publication A- 37), a synthesis of current signal technology that includes a matrix comparing the features of units manufactured both in the U.S. and abroad. The Institute of Transportation Engineers has established an industry-consumer committee to develop technical assistance on APS installations.
When a resident requests the installation of an audible signalor signalsalong a particular route, local traffic engineers may consider a wider range of options today than the audible indicator that chirps or tweets to indicate the walk phase. Units are available that click or buzz at low frequencies and can indicate start times through vibration for people who are both deaf and blind. These units produce sound with less amplification than earlier units and may, therefore, be more acceptable to neighbors. Also available are pedestrian pushbuttons that produce a low-intensity, low-frequency click, allowing pedestrians with vision impairments to locate the control easily. Making the existence and location of the actuating device known to blind users has been a long-standing problem in pedestrian signal design.
In the last decade, development of broadcast signage and similar technologies has also promised to improve access to crossing information for pedestrians who are blind. Applications of intelligent transportation technologies now being deployed on highways may offer other solutions for pedestrians with disabilities.
In responding to a request for an accessible pedestrian signal, the engineer may find it useful to work closely with the blind pedestrian who will be using the intersection and with an orientation and mobility specialist. Mobility specialists can offer a useful perspective, because they are aware of the problems caused by the various types of intersections and because they understand the skills required by blindness. Any APS chosen must be carefully installed and adjusted so as not to interfere with the ability of the blind pedestrian to hear the sound of traffic, which will always remain of paramount concern.
Some mobility instructors suggest that audible pedestrian signals may also be useful to people who have cognitive impairments and to children and older people who have slower reaction times. In fact, recent research in New York City indicated that pedestrian safety in general can be enhanced through the use of recorded announcements at intersections. Providing audible information about crossing time can also speed pedestrian clearance.
Many traffic departments are considering the installation of automatic pedestrian-sensing equipment to trigger walk cycles. Some systems can extend crossing time, if needed, or cancel the signal altogether if the pedestrian crosses early. Such systems are not useful to pedestrians with vision impairments unless there is an audible indication of the crossing interval and a way of identifying intersections that have this type of actuation.
3.5.4 Pedestrian Pushbuttons
Where a pushbutton or other operable device is provided for the use of pedestrians, the mechanism should not require more than 5 pounds (22.2 N) of force to activate. Because outdoor devices will often be used by pedestrians who are wearing gloves or whose movements may be restricted by bulky clothing, it is advisable to select the largest available pushbutton or bar dimension--a 2-inch (50 mm) minimum is recommended-- and to ensure that it is raised above the surrounding surface for ease of operation. Devices that can be operated by a closed fist acting on any point on the surface will be most usable by pedestrians who have mobility impairments.
Pedestrian signal controls should be located within reasonable proximity of the curb ramp and crosswalk. The bar or button should be mounted within allowable reach ranges for pedestrians who use wheelchairs. A height of 42 inches (1065 mm)--the height required for elevator buttons--is recommended. There should be a 30 x 48 (760 mm X 1220 mm) level ground surface centered on each control for a forward or side approach, as appropriate. If a forward approach is provided, the button should be located in the same vertical plane as the leading edge of the clear ground space; if a side approach is planned, the clear ground space should be within 10 inches (255 mm) horizontally of the button. Pedestrians who use wheelchairs should be able to operate the button from a level landing rather than the sloped surface of a ramp.
Pedestrians who are blind should not have to travel more than a few steps to operate a button and then return to the curb to orient themselves for the crossing. It should be clear, by button location and associated tactile signage, which crossing direction is controlled; buttons for different crossings should not be mounted on the same face of a pole, and should be on separate standards if possible. A mounting pole may be used to shield the side of a curb ramp in place of a flared side.
3.5.5 Crossing Times
Crossing times that are based only on the 4-feet-per-second (1220-mm/s) walking speed of able-bodied adults will not be sufficient for pedestrians who do not start to cross immediately after the walk interval begins or whose walking speed is affected by a mobility impairment, stamina, or age (SEE FIGURE 36). Pedestrians who are blind or have low vision, those who have cognitive disabilities, and elderly pedestrians typically delay leaving the curb until they can satisfy themselves that vehicles have stopped.
Pedestrians who use wheelchairs typically travel faster than 4 feet per second (1220 mm/s), but those who use other mobility aids or who have gait or stamina impairments may travel at 1.5 feet per second (455 mm/s) or less. Although the needs of elderly and disabled pedestrians have been widely studied, many of these research projects seem based on prescribing for the special circumstance in which such pedestrians are the only or the primary users of a crossing.
In fact, a truly representative sample of pedestrians would always include a few individuals whose travel speeds fall well below 4 feet per second (1220 mm/s). Options available to the traffic engineer include increasing the crossing time, decreasing the distance (using smaller curb radii or neckdowns and bulbouts that extend intersection corners across the width of the parking lane), subdividing the distance (using medians or refuge islands, with separate pedestrian controls on the median), or providing a pedestrian-actuated control that permits extended-time crossing on demand.
3.5.6 Marked Crossings
In a Canadian study now more than 15 years old, elderly and disabled pedestrians identified marked crossings as the single most valued intersection improvement. Like audible crossing signals, however, the subject of marked crosswalks has generated much industry discussion. Some believe that marked crossings threaten pedestrian safety by leading pedestrians to act on the belief that marked crosswalks offer them some protection. Others maintain that marked crosswalks do protect pedestrians and enhance their safety. Research currently underway for the FHWA may settle this debate. Accessibility provisions requiring the foot of a curb ramp to be contained within a crosswalk, where one exists, suggest that marked crossings are viewed as safety features.
MUTCD marking standards require white lines; where pavement is light colored, black edging is recommended to improve contrast. No test or value for contrast is provided. A 1988 FHWA study found that high-visibility/ladder-type crosswalk markings using a 12- inch (305-mm) stripe with 24-inch (610-mm) spacing had the highest level of motorist recognition. Because juvenile, elderly, and disabled pedestrians are highly dependent on transit, such markings are recommended at crossings that serve bus and other transit stops and stations.
Raised traffic islands should be cut through level with the street (a slight crowning of no more than 1:20 [5%] is permissible if necessary for positive drainage) if it is not possible to provide complying ramps at each curb and a 48-inch-long (1220-mm) level landing between them (SEE FIGURE 37). Designers should avoid offsetting ramps unless crosswalk locations determine such placement, in which case landings and a complying route between them must be provided (SEE FIGURE 38). Because the length of an occupied wheelchair is 48 inches (1220 mm), a cut-through median should provide some additional maneuvering length for safe refuge from traffic. A 60-inch (1525 mm) pedestrian space will accommodate longer wheelchairs and scooters more comfortably.
Raised islands that are cut through may limit wheelchair travel to a single user per crossing cycle. However, wider openings may not give blind pedestrians adequate cues about the presence of a median or the nature of a crossing. In such cases, detectable warnings underfoot can help identify the pedestrian area.
Where two signal cycles are required to complete a crossing, pedestrians with vision impairments should be advised with audible or other signals of the need to wait for the next crossing interval. A locator tone in the pushbutton on the median can provide this information. Devices that tick down the remaining crossing time may be helpful, if both visible and audible output is provided.
3.5.8 Overpasses and Underpasses
Grade-separated walkways, whether air-rights construction over the right-of-way or underground passageways beneath it, should be accessible by ramp or elevator (SEE FIGURES 39 AND 40). Circular or helical ramps do not meet most accessibility requirements, because they cannot accommodate the level landings required for every 30 inches of rise. Furthermore, such ramps produce a differential in slope for inside and outside wheelbases unless very large radii are used.
In suburban and rural areas where the extended right-of-way necessary to ramp a 14-foot- high overpass is not a problem, ramp/landing runs over 300 feet long are not uncommon. Although such ramps meet accessibility criteria, many pedestrians with disabilities would not consider them usable at such lengths. Research with a small group of manual wheelchair users revealed that a majority could not complete a continuous ramp comprising three 1:12 (8.33%) slopes, each rising 30 inches (760 mm) to a level landing between segments) in one sustained effort. Other research suggests that many manual wheelchair users and people who use walking aids have difficulty completing even a single run of this length and slope. Where it is necessary to provide lengthy ramps, it is useful to design more frequent landings and lesser slopes for each successive segment.
In urban areas, elevators are increasingly being installed to serve elevated crossings and upper level walkways in much the same way that two- or three-stop hydraulic elevators have become the common route for below-grade transit access. Elevators are also being used to provide an accessible route on hilly sites (SEE FIGURES 41 AND 42).
Accessibility standards for transportation facilities require a ramped over- or underpass where the accessible route in a transit station crosses a rail line that has a flangeway gap that exceeds 2-1/2 inches (63 mm). FHWA standards promulgated as part of the DOT regulations implementing the Rehabilitation Act of 1973 have long required overpasses and underpasses on Federal-aid highways to be accessible to pedestrians who cannot use stairs.
Items installed for pedestrian use on or along a sidewalk should be accessible. Because
most are single installations at intervals along a sidewalk, each individual location should
provide accessible items. General accessibility provisions for street furniture and related
streetside amenities include the following commonly provided elements.
Specifications for benches that are included in standards for dressing-room facilities and those for fixed seating at counters are not directly applicable to the design of streetscape benches. Pedestrians with disabilities will appreciate walkway seating with a fairly high seat, a shallow front-to-back dimension, a supportive back, and an armrest for making the transition between standing and sitting (SEE FIGURE 43). Although basic accessibility scoping might suggest that only one bench in a grouping needs to meet these recommendations, design consistency and volume-purchasing discounts encourage standardization.
Disabled and elderly pedestrians have expressed strong support for requiring benches at regular intervals along public streets, especially where sidewalks slope steeply. A level area should be provided for the bench.
Public pay telephones are frequently grouped on urban streets. This can permit one instrument to be installed at a wheelchair-accessible height and another to be mounted higher to enable pedestrians who have difficulty bending or stooping to use it easily. Exterior telephones can now incorporate a text telephone (or TTY) for nonvoiced communications, as well, so that a single unit can provide access to most users (SEE FIGURE 44). If only one instrument is provided, it should also be wheelchair accessible. All voice instruments intended for outdoor installations should have volume controls (routinely provided today) and be hearing-aid compatible. Additional information is available from the Access Board publication Bulletin #3: Text Telephones.
3.6.3 Drinking Fountains
Wheelchair-accessible and standing-height drinking fountains should also be combined when installed on public sidewalks, because there may be considerable distances between these fixtures. Both drinking fountains and telephones need to be carefully located to avoid projecting into a circulation route. Note that the minimum knee room required for a drinking fountain27 inches (685 mm)is also the maximum height at which a projection over the sidewalk will be detectable by a pedestrian using a cane.
3.6.4 Sidewalk Toilets
Several manufacturers are now providing and maintaining fixed, single-user toilet units for street-corner installation (SEE FIGURE 45). Accessibility standards require every newly constructed toilet facility to contain accessible fixtures, whether it is for a single user or has multiple stalls.
Portable toilet facilities on a site or in the public right-of-way should also be accessible; at least one unit in each cluster should meet ADA standards. Many of the units that are currently manufactured do not meet accessibility criteria, particularly with respect to turning space. Agencies responsible for the temporary rental of such facilities should compare portable unit specifications to the requirements of accessibility guidelines.
3.6.5 Pedestrian Signage
Pedestrian and street signage that complies with MUTCD will meet most accessibility criteria for character proportion, character height, and contrast, features that are important to pedestrians who have vision impairments. Accessibility standards also require a matte or other nonglare finish (note that non-glare finishes are not incompatible with requirements for reflectivity). Protruding signs must be posted high enough80 inches (2030 mm) above the finished surface in ADAAG and 84 inches (2130 mm) in MUTCDto clear pedestrian routes or be located out of the circulation route. Street signs with large letters are useful to pedestrians who have low vision, because it is usually not possible to view the signs closely.
Pedestrian signals at street crossings should provide a clear distinction between WALK and DONT WALK symbols and should have colors identifiable by readers who have low vision. These pedestrians often find it necessary to use traffic signals on the sidewalk from which they are departing, because pedestrian signals are not distinguishable across a four-lane roadway. Audible or vibrotactile indicators can make such signals more useful to pedestrians who have vision impairments.
Lighting can greatly enhance the accessibility of signs and other orientation information, including crosswalks, curb and curb ramp markings, and barriers and hazard indicators.
3.6.6 Bus Stops
Bus stops and shelters are covered as transportation facilities in accessibility guidelines
adopted by DOT as part of the title II regulation (49 CFR Parts 27, 37, and 38). A route to
and into a shelter and the size of a bus stop pad for the deployment of onboard ramps or
lifts are regulated (SEE FIGURE 46). Bus route identification signs should meet
readability criteria, although tactile signs are not required. Infra-red pedestrian signal
technology has been used in some cities to label bus stops and routes for pedestrians who
use a hand-held receiver. DOTs ADA regulations require that bus stop locations be
audibly and visibly announced on the vehicle.
Transportation stops are considered pedestrian walkways and require curb ramps under the DOJ title II regulation. Because parked cars, traffic, and other conditions can make it impossible for a bus to pull up to a curb along its full length in order to deploy a lift or ramp, a bus stop should be served by a curb ramp so that a passenger may board or exit in the roadway when necessary. Curb ramps at the intersections where the bus stop is located will usually satisfy this requirement, although a curb ramp at the stop may be needed in some locations, particularly at midblock stops and in bus queues.
A common design problem is the location of a new shelter that does not provide adequate maneuvering space for access to and into the enclosure by pedestrians who use wheelchairs. Often, the route into the shelter is obstructed by a waste receptacle or sign. Other shelters are located too close to the edge of the sidewalk to enter without risk of a drop off. Some are located so that the entry route passes over a landscaping strip or tree box where the soil level creates a drop off (SEE FIGURE 47). In systems and on routes where only some buses are accessible, a passenger may be delayed a considerable period of time before boarding and should have shelter while waiting.
3.6.7 Miscellaneous Items
Other items commonly found on sidewalksfire pullstations, mailboxes (including curbside receptacles for overnight delivery services), information and sales kiosks, and fixed vending machinesshould meet basic accessibility requirements for approach, reach range, and operating force and control. Sidewalk passage should not be narrowed by the placement or installation of such items, particularly at turns and ramps and in places that require additional maneuvering space to operate an element or feature.
3.7.1 Temporary Facilities
Facilities and events that temporarily occupy the public right-of-way are not exempted from accessibility requirements (SEE FIGURES 48, 49 AND 50). A street fair, viewing stands along a parade route, the kiosk of a street vendor, and other temporary facilities should all conform to accessibility requirements to the extent that they are covered by title II or title III. Temporary facilities that are part of the construction process itself are exempted.
3.7.2 Temporary Access
In locations where a continuous sidewalk or street crossing route cannot be provided for pedestriansfor example, when construction barricades intervenean alternate route should be available. This may require temporary walkways and curb ramps to maintain access to addresses along a sidewalk obstructed for more than a short time (SEE FIGURE 51).
Sidewalk barriers should be detectable by blind pedestrians or those who have low vision. Plastic tape, movable cones, and print signs at a sidewalk excavation will not generally provide adequate notice or protection. Accessibility provisions for protruding objects and construction barrier criteria in MUTCD offer helpful guidance in this area.
3.8.1 On-Street Parking
Just as the provision of pedestrian circulation on and along sidewalks constitutes a
program of a title II entity, so too may the provision of on-street parking by a city or
town be a program covered by title II. This is particularly true if the local government
does not provide any other public parking in a garage or lot. For many addresses, on-
street parking offers the most convenient access.
It is difficult to be precise in recommending scoping for the number of accessible spaces that should be provided in new construction or alteration projects that include on-street parking. Accessibility scoping for parking lots and garages offers some guidance, but it is not directly applicable to urban blocks or suburban strips. A municipal policy of providing one accessible space per developed block face, in commercial areas where parking is controlled by meters, time limits, or similar regulation, is recommended. In residential areas, citizen requests may establish need and should be coordinated with the provision of curb ramps. The inventory of existing accessible on- and off-street public spaces and opportunities to designate accessible spaces where street slopes are minimal may also be factors.
Where parallel parking is already provided, accessible spaces can be designated at the head and foot of a block to take advantage of existing curb ramp access (SEE FIGURE 52). Locations at or near intersections are also more likely to have minimal street slopes and will be more usable by drivers and passengers who transfer between vehicles and wheelchairs. Spaces at the foot of a block can also accommodate vans that have rear- loading lifts and cars that have rear scooter hoists. If the sidewalk adjacent to an accessible space is unencumbered with plantings, benches, and signposts, vans can deploy side lifts directly on the sidewalk.
Some pedestrians with disabilities who are ambulatory will need accessible parking spaces close to a specific building or facility. Planners should consider providing accessible spaces--and curb ramps--at midblock or in other locations to provide a short or direct route to certain accessible entrances.
3.8.3 Parallel Parking
Although ADAAG does not contain technical specifications for accessible parallel parking, a curb lane that is 13 feet (4 m) wide can accommodate an 8-foot (2440-mm) vehicle width and a 5-foot (1525-mm) access aisle. A curb ramp at the head or foot of the space can then provide access to the sidewalk. If the accessible space is adjacent to the street crossing, an existing corner curb ramp may serve it adequately. Sidewalk extensionsneckdowns or bulboutsused to shorten street crossings or provide traffic calming, can also shelter the access aisle needed for fully usable on-street transfer from vehicle seat to wheelchair. Standard accessible parking signs should be installed. Several State accessibility codes have illustrated on-street spaces with access aisles inset into the sidewalk in the manner of loading-zone construction (SEE FIGURES 53 AND 54).
3.8.4 Other On-Street Parking
Perpendicular and angled on-street parking can be designed and constructed according to accessible parking space provisions (SEE FIGURE 55). Where one-way traffic prevails, it may be necessary to increase the number of access aisles provided or permit backing into the space to locate the access aisle on the side of the vehicle where it is needed. One in every eight accessible spaces should be van accessible, with an access aisle that is 8 feet (2440 mm) wide.
3.8.5 Loading Zones
Accessible design standards for passenger loading zones can be applied at many building entrances by including a curb ramp in front of the building and planning for adequate headroom where there is a canopy or other building element overhead. An access aisle for a vehicle lift can be provided on the sidewalk, if it is clear of obstructions, or a portion of the parking or driving lane may be used, where permitted, for vehicle-to-wheelchair transfer.
3.8.6 Speed Bumps
Drivers with disabilities report that a speed bump (or hump) is a barrier to roadway use, not merely an inconvenience. The jarring that can occur at even low speeds can be painful or dangerous. Other traffic calming approaches should be considered where feasible.
Although the need for roadside callbox systems is rapidly being diminished by the availability of cellular telephones (some new car manufacturers already include car telephones), it is likely that current systems will be maintained and, perhaps, even expanded for some years. Where callboxes are installed as a program of a State or local government, drivers with disabilitiesboth those who use wheelchairs and those who do not communicate by voicemust have a means to take advantage of the emergency help they offer.
Several jurisdictions now require that TTYs be installed at roadside callboxes. It is less
common to provide callboxes that are physically accessible for a person who uses a
wheelchair. Providers have voiced concerns about the safety of people with disabilities
traveling on or along the shoulder of a high-speed roadway. It is true that pedestrian use
of the breakdown lane can be dangerous, but people who use wheelchairs have expressed
the need to have the same options to seek help as other drivers and have taken action,
including filing lawsuits, to ensure the availability of those options. To be accessible to a
pedestrian who uses a wheelchair, a callbox must be approachable from the shoulder
without obstruction and should be mounted so that its highest operable part does not
exceed side- or front-reach range limits. FHWA has indicated that boxes mounted at that
height on breakaway supports do not pose a breakaway hazard to drivers. Manufacturers
caution that care must be taken to ensure that snow is not plowed under or over callboxes
installed at lower heights.
FHWA-sponsored research conducted in the early 1980s resulted in the publication of several pedestrian manuals that recommend accessible design criteria. The 1989 FHWA publication Handbook on Planning, Design, and Maintenance of Pedestrian Facilities (Zegeer, et al.) was the first to integrate accessibility and general pedestrian considerations. Its design recommendations are generally consistent with ADAAG and UFAS provisions and with this guide.
Recently, as part of the National Highway System Designation Act of 1995, FHWA issued an interim final rule adopting design standards promulgated by AASHTO in its 1995 edition of A Policy on Geometric Design of Highways and Streets. Chapter II (Design Controls and Criteria) of the Green Book, as it is known, contains a discussion on designing to meet the needs of people with disabilities that reflects ADA implementing regulations. Chapter IV (Cross Section Elements) also refers to some accessibility criteria.
Industry organizations, including AASHTO, the American Society of Civil Engineers, the Institute of Transportation Engineers (ITE), the American Public Works Association (APWA), the National Committee on Uniform Traffic Control Devices, and others, have begun to incorporate appropriate accessibility provisions in organization guidelines and good practice recommendations as they are updated. Recent publications include Design and Safety of Pedestrian Facilities (ITE Technical Committee 5A-5, 1998) and Standard Plans for Public Works Construction (APWA, 1994). Changes in chapters on markings, signals, and traffic-control devices at railroad-highway grade crossings in MUTCD will be undertaken in 2000. Disability organizations are expected to provide detailed comment in several areas, particularly on accessible pedestrian signals.
TEA-21 legislation requires that FHWA, in concert with AASHTO and ITE, develop guidance on pedestrian and bicycle design and construction, including accessibility features. A joint industry/consumer task force will assist. AASHTO has proposed to undertake the development of Pedestrian Guidelines over the next two years. A National Cooperative Highway Research Program (NCHRP) project on the planning, design, and operation of pedestrian facilities, including requirements for accessibility, is also underway.
3.9.2 Technical Assistance
Questions about the design of accessible public rights-of-way and related pedestrian facilities may be addressed to the following DOT offices:
Compliance and enforcement issues and questions about program accessibility in existing facilities should be directed to the Department of Justice ADA information line at 800/514-0301 (V) or 800/514-0383 (TTY). Copies of the DOJ title II regulation may be ordered through the same telephone number. The Department also publishes a Title II Technical Assistance Manual (DOJ TA Manual) and a quarterly enforcement report. The DOJ ADA website can be found at: www.usdoj.gov/crt/ada/adahom1.htm.
Questions about the ADA Accessibility Guidelines, including future rulemaking on public rights-of-way accessibility, should be addressed to the Access Board technical assistance (TA) line at 800/872-2253 (V) or 800/993-2822 (TTY) between 10:00 a.m. and 5:30 Monday through Friday (no technical assistance after 2:00 pm on Wednesdays). Requests may also be faxed to the Board at 202/272-5447 (F). Copies of ADAAG may be obtained through the same Access Board information line. Also available are a series of technical bulletins on ADAAG provisions; ADAAG and UFAS manuals and checklists; a nine-part transit manual for system administrators; an accessibility newsletter; several research publications, including the report of the Recreation Advisory Committee; and copies of Access Board rulemaking notices. A four-part training videotape, Accessible Sidewalks: Design Issues for Pedestrians with Disabilities is available on request.
Many Access Board documents, including ADAAG, can be downloaded from the Boards website at: http://www.access-board.gov. Arrangements can be made through the Access Board for specialized training for design professionals, transportation engineers and planners, and others responsible for applying accessibility guidelines to new construction and alterations.
Background and Role of TEA-21
More than $100 billion is spent every year on our nations highways by all units of government. This remarkable annual investment in roads is financed from a variety of Federal, State and local sources, including user fees, general funds, bond issues, and toll revenues. The Federal government collects approximately one-quarter of these funds through the Federal gasoline tax and redistributes almost all of the money that is generated to States and metropolitan areas to spend on their priorities, within certain programs and funding categories.
The Transportation Equity Act for the 21st Century (TEA-21), signed into law on June 9, 1998, determines the program areas and funding categories, in particular by defining what kind of activities are eligible for different pots of federal money. TEA-21 is one in a long line of transportation laws that, since 1956, has helped direct and lead transportation expenditures in the United States at the Federal, State and local level. In addition to setting funding priorities, the law also sets out certain planning and policy requirements for States and metropolitan areas.
Funding Opportunities for ADA Improvements
Most of the major categories of funding in TEA-21 can be used to build or retrofit sidewalks, crosswalks, and other accessible pedestrian facilities such as trails. Major funding sources include:
All of these programs confer eligibility for funding on pedestrian-related projects and
activities. However, few of the programs have any guaranteed minimum amount of
funding that must go to improving access for people with disabilities -- the decisions as to
what gets funded and what does not are made at the State DOT and Metropolitan
Planning Organization (MPO) level and the choices are made as part of a prescribed
planning process that is described below. People or agencies seeking funding should note
that Federal funds can only be used for projects that are in an approved State or MPO
Transportation Improvement Program (TIP).
Those seeking funding should also note that funding for specific improvements can either be approved as an independent or stand-alone project, as an incidental part of a larger transportation project, or as part of a grouped type or list of similar activities (such as an annual program to improve a certain number of intersections to include curb cuts and crosswalks).
TEA-21 Planning Process
The transportation planning process established in 1991 as part of the Intermodal Surface Transportation Efficiency Act is continued by the Transportation Equity Act for the 21st Century. States and metropolitan areas (with populations of more than 50,000) are required to plan for the development and integrated management and operation of transportation systems and facilities (including pedestrian walkways and bicycle transportation facilities) that will function as an intermodal transportation system...
The planning process for both States and metropolitan areas is further required to consider projects and strategies that will increase the safety and security of the transportation system for nonmotorized users; increase accessibility and mobility options available to people; improve the quality of life; and enhance the integration and connectivity of the transportation system for people. States and MPOs are required to produce two basic planning documents: a Long-range Transportation Plan and a Transportation Improvement Program (TIP). The Long-range Transportation Plans have at least a 20-year horizon and must be regularly updated (every three years in metropolitan areas that do not meet federal air quality standards; every five years in other metropolitan areas; and periodically in States). The TIPs must list approved projects for which there is identified funding for each of the following three years, and must updated at least every two years.
The Long-range Transportation Plans set the long term direction for transportation investment and typically include a broad vision statement, long-term goals and objectives, policy statements and priority areas for the State or metropolitan area. They may identify specific projects (such as road improvements or new transit construction), important corridors that need study, or programmatic areas (such as improving access for people with disabilities) that will receive special attention. Coverage of pedestrian issues may be integrated into the overall transportation plan or contained in a separate pedestrian plan that is incorporated by reference into the overall plan. In the latter instance, a separate pedestrian plan may well contain planning and design guidance related to sidewalks, crosswalks and other pedestrian facilities that will essentially determine how pedestrian infrastructure is developed in the years ahead.
The TIPs are quite different documents as they usually are little more than a long list of the specific projects that are going to be undertaken by the State or MPO in each of the following three years, each with a short description of the actions to be taken. Every project in the TIP must be consistent with projects, programs or policies contained in the long range plan and must have an identified source of funding.
The Long-range Transportation Plans and TIPs must be developed and approved through a process that gives the public, affected groups and agencies notice of and a reasonable opportunity to comment on the plans as they are developed. There are detailed federal guidance documents which outline the kind of public involvement activities that are sufficient to provide appropriate notice and opportunity for people to participate in the planning process, but there are few firm requirements that can be enforced.
At a minimum, public involvement should be proactive and provide complete information, timely public notice, full public access to key decisions, and opportunities for early and continuing involvement... (23 CFR 450.212 (a)), and must provide for:
State and local government facilities and programs are covered by title II of the
Americans with Disabilities Act of 1990 (ADA); private sector facilities are covered by
title III. Federal facilities and programs are subject to the Architectural Barriers Act of
1968 (ABA) and the Rehabilitation Act of 1973 (often called 504'). In addition to ADA
title II coverage, Federally-assisted state and local government programs may also be
subject to the Rehabilitation Act. Private sector facilities are subject to title III of the
State and local governments may choose to follow either the ADA Accessibility Guidelines (ADAAG) or the Uniform Federal Accessibility Standards (UFAS) for new construction and alterations under the ADA. UFAS is also the standard for ABA and Rehabilitation Act coverage (although many Federal agencies have directed that ADAAG be used where it provides a higher degree of accessibility). ADAAG is the only standard for title III (private sector) facilities.
Copies of the US Department of Justice (DOJ) ADA title II and title III regulations and their companion Technical Assistance Manuals can be obtained from DOJ by calling 800/514-0301 (V) or 800/514-0383 (TTY). Copies of UFAS and ADAAG may be obtained from the US Architectural and Transportation Barriers Compliance Board (the Access Board) via its toll-free technical assistance line at 800/872-2253 (V) or 800/993- 2822 (TTY).
Other accessibility resources with application to pedestrian facilities include:
Design and Safety of Pedestrian Facilities
A Recommended Practice of the Institute of Transportation Engineers
ITE Technical Committee 5A-5 (1998)
Institute of Transportation Engineers
525 School Street, SW
Washington, DC 20024-2797
--see Chapter 2: Pedestrians with Disabilities
Sidewalk and Curb Ramp Design
State of New Mexico
Governors Committee on Concerns of the Handicapped
Lamy Building, Room 117
491 Old Santa Fe Trail
Santa Fe, NM 87503
505/827-6465 (V); 505/827-6329 (TTY); 505/827-6328 (F)
A Working Approach to Accessibility in Public
Montana Department of Transportation
Darren Kaihlanen and Scott A. Keller, PE
MDT/MSU Design Section
204 Cobleigh Hall
Bozeman, MT 59717-3900
406/994-1843 (V); 406/994-1870 (F)
--curb ramp designs in Microstation CADD and Adobe Acrobat available at MDT
Designing Sidewalks for People Who Use Wheelchairs
Beneficial Designs, Inc.
5858 Empire Grade
Santa Cruz, CA 95060
Street Design Guidelines for Blind and Visually Impaired Pedestrians
American Council of the Blind
1155 Fifteenth Street NW, #720
Washington, DC 20005
Accessible Sidewalks: Design Issues for Pedestrians with Disabilities (video, TRT 43 minutes)
US Architectural and Transportation Barriers Compliance Board
1331 F Street NW, #1000
Washington, DC 20004
800/872-2253 (V); 800/993-2822 (TTY); 202/272-5447 (F)
--also available: Report of the Recreation Access Advisory Committee
--also available: ADAAG Technical Assistance Manual
Accessible Pedestrian Signals (APS)
Billie Louis Bentzen, PhD and Lee S. Tabor, AIA
Accessible Design for the Blind
PO Box 1212
Berlin, MA 01503
--synthesis of current (1998) APS technology and practice
--listing of US and foreign manufacturers
--also available from research sponsor, the US Access Board (see above)
ADA Standards for Accessible Design (videotape series)
Center for Universal Design
North Carolina State University, School of Design
Raleigh, NC 27695-8613
Best Practices in Walkway and Trail Design
Beneficial Designs, Inc.
5858 Empire Grade
Santa Cruz, CA 95060
--also be available from research sponsor FHWA
Universal Access to Outdoor Recreation: A Design Guide
1802 Fifth Street
Berkeley, CA 94710
--also available: The Accessibility Checklist: An Evaluation System for Buildings and Outdoor Settings (1993) and Play for All
Guidelines: Planning, Design and Management of Outdoor Play Settings for All Children (1993)
Everyones Nature: Designing Interpretation to Include All (1994)
by Carol Hunter/Colorado Division of Wildlife
Falcon Press Publishing Company
Design Standards to Accommodate People with Disabilities in Park and Open Space Design
by Michael L. Reis (1991)
University of Wisconsin-Extension
Trail Intersection Design Guidelines
Wayne E. Pein, University of North Carolina Highway Safety Research Center
available from the UNC Highway Safety Research Center
730 Airport Road, Campus Box 3430
Chapel Hill, NC 27599-8710
--also available from research sponsor FHWA
Spotlight on Safety
A series of pedestrian safety brochures sponsored by the Partnership for a Walkable America
Highway Safety Research Center
University of North Carolina
730 Airport Road, Campus Box 3430
Chapel Hill, NC 27599-3430
919/962-2202 (V); 919/962-8710 (F)
ADA Self-Evaluation Handbook for Park Districts
National Parks and Recreation Association
2775 South Quincy Street, Suite 300
Arlington, VA 22206-2204
--also available from NRPA: Recreation Access in the 90s Newsletter (bi-monthly)
Title II Action Guide
Barrier Free Environments/Adaptive Environments Center
available from LRP Publications
747 Dresher Road, PO Box 980
Horsham, PA 19044-0980
800/341-7874, x353 (V)
Title II Technical Assistance Manual
U.S. Department of Justice
800/514-0301 (V); 800/514-0383 (TTY)
--also available: 28 CFR Part 35: Nondiscrimination on the Basis of Disability in State and Local Government Services; Final Rule (title II)
Park Access Digest (monthly) and other publications and workshops
517 Lincoln Avenue
Redwood City, CA 94061
Park Practice Program Publications (three quarterly publications: Trends, Grist, and Design)
National Park Service
PO Box 37127
Washington, DC 20013-7127
--see Accessibilty and Outdoor Recreation (Trends: v. 33, no. 1, 1996)
Disabled Outdoors Magazine
5223 South Lorel Avenue
Chicago, IL 60638
Sports n Spokes (bi-monthly magazine)
Paralyzed Veterans of America
2111 East Highland Avenue, #180
Phoenix, AZ 85016-4702
Bicycle and Pedestrian Planning Under ISTEA:
National Highway Institute
US Department of Transportation/Federal Highway Administration
--Participant Workbook: Publication # FHWA-HI-94-028 (September 1994)
Pedestrian and Bicycle Safety and Accommodation: Course #38061
National Highway Institute
US Department of Transportation/Federal Highway Administration
Introduction to Wheeling and Long Distance Racing (video)
Vinland National Center
PO Box 308
Loretto, MN 55357
National Wheelchair Athletic Association Videotapes
Wheelchair Athletics of the USA/NWAA
1604 East Pikes Peak Avenue
Colorado Springs, CO 80909
ADA TECHNICAL ASSISTANCE
US Architectural and Transportation Barriers Compliance Board (the Access Board)
800/872-2253 (V); 800/993-2822 (TTY); www.access-board.gov
US Department of Justice
800/514-0301 (V); 800/514-0383 (TTY); www.usdoj.gov/crt/ada/adahom1.htm
US Department of the Interior/National Park Service
(by contract with the National Center on Accessibility at Indiana University)
US Department of Transportation
--FHWA Office of Engineering/Federal-aid and Design Division/Geometric, Safety and Design Group: 202/366-0494
--FHWA Office of Environment and Planning/Bicycle and Pedestrian Programs: 202/366-4634 (V)
--FHWA Office of Civil Rights: 202/366-0693 (V) or 202/366-5751 (TTY).
--Departmental Office of Civil Rights: 202/366-4648 (V) or 202/366-8538 (TTY)
--FTA Office of Civil Rights: 888/446-4511 (V); 202/366-4018 (V); 202/366-0153 (TTY)
--FTA Office of Planning: 202/366-4033
Regional Disability and Technical Assistance Centers (10 regions)
National Center on Accessibility (in cooperation with the National Park Service)
The Americans with Disabilities Act (ADA) requires that new and altered public
sidewalks and street crossings be accessible so that people with disabilities can use the
pedestrian routes that connect buildings, facilities, and transportation modes. Title II of
the ADA covers new sidewalks and streets constructed by or on behalf of a State or local
government. The Department of Justice (DOJ) title II regulation specifically requires that
curb ramps be provided when sidewalks or streets are newly constructed or altered.
Sidewalks and curb ramps covered by title II should comply with the technical standards
in ADAAG, UFAS (the 1984 standard for Federal construction), or other accessibility
code that meets or exceeds the level of accessibility required under the ADA. Many of
the same provisions that govern the accessible route on a building site or within a
building, as specified in the ADA Accessibility Guidelines (ADAAG, sections 1-10), can
also be applied to public sidewalks. Additional requirements for existing pedestrian
networks not otherwise being altered are also included in the DOJ regulation.
OTHER PEDESTRIAN FEATURES
Accessible Sidewalks and Street Crossings: a Design Guide
Written by: U.S. Access Board and Federal Highway Administration staff
Edited by: Lois Thibault, U.S. Access Board
Illustrations by: Scott Lewendon, LandTech
Designed by: Ziv Gil, Ziv Communications
Particular thanks go to Julie Zirlin, U.S. Department of Transportation, whose commitment made this publication possible and Ellen Harland, AIA, U.S. Department of Justice, whose graphics laid the groundwork for the illustrations.
Many people helped in producing and advising on this publication, among them Nick Artimovich, Andy Clarke, Marguerite Dicenzo, Christopher Douwes, John Fegan, Nancy Johnson, and Barbara McMillen (FHWA); Dennis Cannon, Marsha Mazz, Jim Pecht, and Scott Windley (U.S. Access Board), Elizabeth Bacon (DOJ), Bill Hecker, AIA; Jerry Markesino, PE, Ken Kobetsky, PE and AASHTO reviewers, Julie Carroll, Sam Prestipino, Scott Keller, PE, Eric Dibner, and Allan Hockett.
U.S. Architectural and Transportation Barriers Compliance Board http://www.access-board.gov
1331 F Street NW, Suite 1000, Washington, DC 20004-1111
TECHNICAL ASSISTANCE LINE V:800/872-2253 or TTY:800/993-2822
All illustrations are by Scott Lewendon.
Thanks to Bill Hecker, AIA, Jean Tessmer, David Grenier, Tom Pack, and Casey Yanagihara for concepts illustrated in Figure 11 and to Bill Hecker for Figure 23.
3/Downtown Improvement Program: Auburn, AL (F. Allan Hockett)
5/Protruding objects (Access Board archives)
6/Split sidewalk: Washington, DC (Lois Thibault)
7/Building entrance ramp: Washington, DC (Lois Thibault)
12/Protruding objects (Access Board archives)
27/Transitions (Sam Prestipino)
28/Transitions (Lois Thibault)
29/Transitions (Access Board archives)
30/Transitions (Access Board archives)
33/Raised crossing: Cumberland, MD (Lois Thibault)
34/Elevated sidewalks: Silver City, NM (Eric Dibner)
35/Detectable warnings: Harrisburg, PA (Lois Thibault)
36/Walking speed (Lois Thibault)
38/Curb ramps at splitter island: Washington, DC (Lois Thibault)
39/Pedestrian overpass: La Jolla, CA (Lois Thibault)
40/Elevator access to steeply sloping site: La Jolla, CA (Lois Thibault)
41/Public sidewalk elevator: Lynchburg, VA (F. Allan Hockett)
42/Public sidewalk elevator: Lynchburg, VA (F. Allan Hockett)
43/Sidewalk benches (Access Board archives)
44/Exterior text telephone (Ultratec)
45/Sidewalk toilets: San Francisco (JC Decaux)
46/Bus stops (Lois Thibault)
47/Bus stops (Lois Thibault)
48/Temporary facilities: Washington, DC (Lois Thibault)
49/Temporary facilities (Lois Thibault)
50/Temporary facilities (Lois Thibault)
51/Temporary access: Albuquerque, NM (Lois Thibault)
52/On-street parking: Alexandria, VA (Lois Thibault)
53/Accessible on-street parallel parking: Rockville, MD (Lois Thibault)
52/On-street parking: Alexandria, VA (Lois Thibault)
53/Accessible on-street parallel parking: Rockville, MD (Lois Thibault)
54/Accessible on-street parallel parking: Rockville, MD (Lois Thibault)