|October 28, 2002|
Subject: Draft ADA Standards for Public Rights of Way Accessibility Guidelines
Multnomah County Land Use Planning and Transportation Division appreciates the opportunity to comment on proposed ADA guidelines for Accessible Public Rights-of-Way. We appreciate the importance and necessity for these guidelines in making the street environment safer and more accessible for persons with disabilities
We have reviewed the draft standards and considered how they would affect the programs and services that our Agency provides. We do not want to overemphasize the financial impact of the proposed standards; however, the financial impact cannot be ignored. For some projects, the additional cost imposed by the standards would be minimal. However, the cumulative effect of some aspects of the guidelines will result in substantial increases in project costs and fewer projects being performed within current funding levels. We provide examples of such situations in the comments that follow.
As a general comment, we believe it would be very useful to professional designers, if the standards and guidelines were delineated in a manner that utilized and differentiated the terms standard, guidance, and option.
To this end, we recommend that the Access Board consider The Manual on Uniform Traffic Control Devices (MUTCD) as a model for this approach. By differentiating between standard, guidance, and option, the MUTCD provides standards and flexibility to the professional design community that promote uniformity on key elements of the system, yet allow for innovative solutions to specific site conditions. Without additional flexibility, the draft ADA standards run the risk of being too prescriptive, inhibiting innovative and cost-effective solutions to accessibility issues.
Flexibility needs to be maintained because local topography presents unique design challenges that cannot be fully envisioned and addressed when preparing general design standards. If flexibility is too narrowly constrained, then applying the guidelines will be extremely challenging because of the variety of site conditions encountered.
Following are several additional comments and suggestions we recommend for consideration of the Access Board. In some cases, we have presented these as statements and recommendations. In other cases, we have presented these as questions that we ask for the purpose of clarification.
Existing Public Rights of Way (1102.2)
The guidelines seem to divide improvements into “additions” and “alterations.” We suggest that additional guidance be provided on the differences between additions (new construction) and alterations and when certain provisions apply.
1102.2.2 states, “Where existing elements or spaces in the public right-of-way are altered, each element or space shall comply with the applicable provisions of Chapter 11.” The addition of the word “space” causes some additional confusion. We offer the following situations and ask whether these are interpreted to be “alterations” or “additions.”
• Example A: A corner is proposed to be reconstructed to install curb ramps. Ramps can be constructed at appropriate grades and widths.
o Suppose the landings will be too small unless the signal pole and pushbuttons are relocated. If the signal pole cannot be relocated without right-of-way acquisition, does that constitute “technical infeasibility?”
o If the signal pole and push buttons are relocated to allow appropriate ramps and landings, do provisions of 1106.3 Pedestrian Pushbuttons apply because the signal was altered?
o Does the alteration of the corner (arguably a “space”) require meeting the provisions of 1106.3 even if the poles and signal system are not otherwise altered?
• Example B: A new intersection is created where a subdivision street is designed to intersect with an existing arterial street. The existing grade of the arterial street is 6 percent. Given that the existing arterial has a grade of 6 percent, sidewalks along the arterial can match that grade. However, the new subdivision will create a new intersection and new crosswalks.
o Are the new intersection and the new crosswalks required to meet the 1:48 (2 percent) slope requirements for both cross slope and running slope?
o If “yes,” how do we deal with the steeper section along the arterial caused by flattening the intersection?
o Does the answer change if the arterial street has an underlying grade of only 4 percent?
We support the exception for alterations based on a determination that they are “technically infeasible.” We suggest that there should be exceptions for new construction based on “technical infeasibility.” We are not, however, suggesting that the standards for determining feasibility should be the same for alterations or additions.
Alternate Circulation Path (1102.3, 1111)
We support the provision of a signed alternate circulation route during maintenance and construction activities. However, we would like to see a degree of flexibility and a provision for exceptions to this requirement where it is not feasible for safety reasons.
Multnomah County has many roadways with five motor-vehicle lanes, bike lanes and five-foot curb-tight sidewalks. When we repair or make improvements to the sidewalk, we often have to close the curb lane for the construction activity. The lane is occupied by backhoes, dump trucks, concrete trucks, etc. When space behind the sidewalk is not available, the alternate circulation path would have to be moved into the second motor vehicle lane. With sufficient barricades and markings, this could be made safe, but it could not be easily re-established each workday and would have to stay in place from the beginning of the project its end. The resulting closure of two lanes in the same direction would require shifting the on-coming traffic to a single lane. Even if this proved feasible in mid-block locations, it would be especially difficult at intersections. Shifting motor-vehicle traffic two lanes to the left would likely put them out of the cone of vision for the existing traffic signals and could potentially require flaggers for the operation of the intersection. Such changes in traffic operations would significantly reduce intersection capacity and quite possibly make it impossible to give pedestrians access to push buttons to actuate the WALK signal. In this example, providing an adjacent alternate circulation path could create a public safety problem for both pedestrians and motorists.
The draft guideline is too prescriptive in our opinion. We suggest the standard be the provision of a safe alternate circulation path and the guidance should give preference to a route that does not involve a shift to the opposite side of the street or other circuitous route. Reducing adverse impacts to persons with disabilities is an important consideration during construction and maintenance activity. However, in some cases, a short-term interruption of access may be safer and more prudent than an alternate circulation path for an extended period. The proposed guidelines do not allow design professionals or even policy makers,who are ultimately responsible for balancing the needs of all transportation system users, to make that decision.
Section 1111.5. This also makes reference to a “disrupted pedestrian access route.” We are uncertain of the meaning of this. Does a “disruption” refer to an alternate circulation path, a closure, or something else entirely?
Protruding Objects (1102.5). This section limits the protrusion to 4 inches for any object between 27 and 80 inches above the surface. We note that the MUTCD provides for traffic signs to be mounted 7 feet above the pavement and for supplemental signs to be mounted up to one foot lower. Multnomah County makes a special effort to ensure that our signs meet these mounting heights. The typical supplemental sign mounted as little as 6 feet above the sidewalk is a 12-inch by 18-inch “NO PARKING” sign. Since the nominal 4x4 post on which we mount signs measures only 3-½ inches, our signs protrude 4-¼ inches into the sidewalk area. For agencies that use 2-inch channel or pipe, the protrusion would be 5 inches. We recommend that the protrusion standard be reviewed to see, if slight modifications would be appropriate to allow sign-mounting practices allowed in the MUTCD to continue.
It appears that the protrusion aspects of the guidelines would allow downward-sloping guy wires that run parallel with the sidewalk, but would clearly preclude them from crossing a pedestrian access path. Is it appropriate to allow downward-sloping guy wires anywhere along the pedestrian path?
Pedestrian Access Route (1103)
Clear Width (1103.3). This section specifies a minimum clear width of 48 inches. We agree with this specification, but suggest it should be modified to increase the minimum to 60”, where bollards or similar devices are installed specifically to restrict motor-vehicle entry.
Surface Gaps at Rail Crossings (1103.7). We support the concept of minimizing gaps at rail crossings. We suggest the Board consider the implications of crossings that occur at angles other than 90 degrees. This may be more important than the gap measurement itself.
Detectible Warnings (1103.7.1). We find this confusing. Does this section mean that a sidewalk adjacent to a road does not require a surface warning treatment at a rail grade crossing? Or is “detectible warning” something different in this context?
Pedestrian Crossings (1102.8, 1105)
Crosswalks (1105.2). The running slope and cross slope requirements may result in a significant increase in road maintenance costs for pavement overlays and strengthening. A widespread pavement overlay technique is to place a greater asphalt depth in the center of the road and a lesser depth at the gutter. This technique increases the strength of the pavement where traffic loads are greatest and avoids the cost of removing pavement at the pavement edges where adequate curb exposure must be maintained. However, since this technique increases the crown of the road, it could cause a road to exceed the proposed slope requirements. The more expensive and time-consuming method involves grinding and removing the existing pavement surfaces. Grinding and removal of existing pavement can result in pavement damage that must be repaired, reduced pavement strength, and more frequent pavement treatments. The guidelines as drafted will have this effect.
We recommend that slope requirements specified in the proposed rules apply to new construction only and that a slightly greater slope be allowed on existing roadways in way that allows some flexibility for road maintenance overlays.
Communities located in areas with steep topography will not be able to meet the proposed cross slope requirements without extensive alteration of existing roadways. We recommend that topography and slope of the underlying terrain be specifically mentioned as exceptions, based on a finding that compliance is technically infeasible.
Pedestrian Signal Phase Timing (1105.3). We believe it is overly restrictive to require the pedestrian clearance time be calculated using a pedestrian walk speed of 3.0 feet per second. We fully support the use of that speed where the need is apparent and we currently use such a speed in our calculations where we have observed or had requests for an extended clearance time. We
have found that longer pedestrian change intervals can completely disrupt signal timing progression in major corridors and can cause substantial increases in delays for both major street and minor street traffic. These factors can reduce overall system efficiency and increase air pollution. Longer cycle lengths may also increase the incidence of running red lights by motorists and decreases in safety.
We recommend that 4.0 feet per second be retained as the standard, but that guidance be provided with a lower walking speed (3.0 feet per second) where conditions warrant that based on engineering judgment.
Surfaces (1104.3). The proposed guidelines prohibit gratings, access covers, and/or other appurtenances in curb ramps, landings, blended transitions, and gutter areas within pedestrian access routes. We agree with this in concept, but find there are so many conflicting needs at corners that our options are severely limited with regard to placement of traffic signal junction boxes at signalized intersections. We suggest that leeway be allowed to place access covers in landings, if it is not practical to locate them elsewhere. We support the prohibition of such items in ramps, transitions, and gutter areas.
Pedestrian Overpasses and Underpasses (1105.5). The guidelines propose requirements for an elevator where the rise of ramped approach exceeds 60 inches. We find this far too restrictive and believe it will be a deterrent to constructing under- and overpasses for improved pedestrian movement.
There appears to be an inconsistency between section 1105.5.2, which specifies that the running slope shall not exceed 1:20, and 1105.5.3, which applies when the slope exceeds 1:20. We suggest this inconsistency be resolved or explained.
We also question whether 48 inches is an adequate minimum width for an approach unless it is for a very short length.
Roundabouts (1105.6). The proposed requirements for pedestrian activated signals severely compromises use of a roundabout as a means of accommodating traffic at an intersection. We urge further research and evaluation be conducted. We suggest that different treatments may be appropriate depending upon the number of approach lanes and the design speed used for individual roundabouts.
Accessible Pedestrian Signal Systems (1102.8, 1106)
There are many conflicting requirements and site conditions at intersections that the professional designer must address to provide safe and convenient pedestrian crossings. The proposed guidelines significantly restrict the ability to optimize a design that best meets the constraints encountered. While we understand the rationale for most of the elements individually, we are concerned about their interrelation and our ability to meet all of them simultaneously, especially in situations where topography and right-of-way limitations severely limit the options.
Location (1106.2.1). The concept of separating the individual signal access buttons by a distance of 120 inches is questionable based upon local observations. We think this will be very difficult to achieve at any intersection where there is significant grade on either road approach. The proposed guideline of separating the signal access buttons on individual pedestals 120 inches apart is not uniformly endorsed by the disabled community as an enhancement for coping with crossing a congested intersection. We recommend that the Board carefully review this guideline and solicit additional input from the disabled community. The single-pedestal design standard currently being used in Multnomah County appears to be very functional and provides good service to the disabled community.
This section also requires that the control face of the device face the intersection and be parallel to the crosswalk it serves. We prefer this location and orientation, but find this requirement to be very limiting. We recommend that the side-mount orientation (perpendicular, rather than parallel) also be permitted as long as visual and tactile explanations are provided for that push button. Our concern is that terrain and other space limitations may preclude the prescribed orientation when combined with the required size and slope of landings and ramps.
The requirement that the push buttons be located between 30 inches and 120 inches behind the curb will be problematic, especially where a street has a considerable grade. The 120-inch maximum gives little leeway, especially when it is combined with the required button orientation. A seven-inch curb requires a ramp with a minimum length of 84 inches. Adding a 48-inch landing allows only 12 inches within which to locate the button. Due to conflicts with underground utilities and other immovable obstructions, we find it difficult to place our signal poles with this level of precision. We recommend that this spacing requirement be softened to a recommendation status rather than a requirement implied by the word “shall.”
Volume (1126.96.36.199). The requirement for the volume to be responsive to ambient noise-level changes may be problematic. We suggest the requirement be softened from the mandatory “shall” to the suggested “should.”
Multnomah County is supportive of the effort to improve accessibility to the transportation system for all our citizens. We support the effort to standardize the systems to make it easier for persons with disabilities to navigate our community. We applaud the Access Board’s efforts to provide guidance. We ask, however, that the Board give more consideration to the difficulties of implementing some of these concepts, especially as they relate to the variability of terrain with which we have to work. We specifically ask that the Board revise the guidelines to clearly differentiate between standards that must be achieved and those areas where a little flexibility can be granted.
Harold Lasley, P.E., Director
Multnomah County Transportation Division
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