John E. Cameron, P.E.
|October 28, 2002|
Re: Comments on “Draft Guidelines for Accessible Public Rights-of-Way”
Public Rights-of-Ways have many users and functions, pedestrians, personal vehicular, commercial vehicular, public transit, public drainage and utilities just to name a few. Many of these users have legal rights to occupy and utilize the Rights-of-Ways. In fact, the Federal Communications Commission is currently studying regulations that would give telecom companies additional rights associate with public Rights-of-Ways. Operators of Rights-of-Ways must balance the needs and the rights of all users to make the safest and most efficient use of the public Rights-of-Ways.
There are a myriad of agencies, industries and private interest groups that all have input to how the Rights-of-Way are configured and used. Design of projects within the public Rights-of-Ways is guided by government regulation and policy, as well as accepted design practice. In the course of developing a design for a project, there are always compromises which must be made. The inflexibility of the language of the Draft Guidelines may work at cross-purposes to the interest, and indeed the safety of some of the other users of the public Rights-of-Ways. The Draft Guidelines in their current form, if adopted by the DOJ, would carry the force of Federal Regulations and could not be deviated from.
The lack of clear definition to terms such as “alteration” and “technically infeasible” leave them open to different interpretations.
In the end, if the Guidelines are adopted as written, the door will be open for a raft of litigation. The definition of “alteration” and “technically infeasible” will be hammered out in case law. Designers will feel compelled to place the ADA requirements above other generally accepted design practices that have evolved over the years as a matter of public safety. This could lead to more litigation for not following generally accepted design practices. Overall, the guidelines would have a chilling effect on public projects, many of them safety related, as the case law develops. I urge the Access Board to carefully review the language of the Draft Guidelines prior to adopting them. Definitions of terms, along with their intent, should be made plain. A degree of flexibility should be introduced to some of the language. It may be appropriate to hold some sections until further research can be done to determine their impact.
The following are my specific comments:
Section 1126.96.36.199 Prohibited Reduction in Access - Does this section require that alterations in the public Rights-of-Ways have to include providing accessibility meeting the requirements of new construction for site arrival points to private buildings or facilities adjacent to altered public Rights-of-Ways? This needs clarification. If this is the intent, it means municipalities will be responsible for providing accessibility to private buildings or facilities even if they were not accessible before the alteration. Should all site arrival points, facility access points be made accessible? Who would decide which site arrival points or facility access points should be made accessible?
This would be a huge transfer of responsibility from the private sector to the public sector which would have incalculable cost to the taxpayer.
I would suggest the following wording: An alteration that decreases or has the effect of decreasing the accessibility of a public right-of-way below the requirements for new construction at the time of the alteration is prohibited. An alteration shall not decrease accessibility of site arrival points to buildings or facilities adjacent to the altered portion of the public right-of-way.
Section 1102.7 Pedestrian Signs - All signage within the public Rights-of-Ways should comply with MUTCD so that differing standards will not cause confusion. MUTCD standards provide nationwide consistency in signage, which reduces the chance of misinterpretation.
Section 1102.7 Pedestrian Signs - Introduction of Pedestrian Signs may create protrusions in conflict with Section 1102.5.
Section 1102.10 Stairs - Is the requirement for a stripe of contrasting color on the stair tread different from that of other public facilities such as parks, and recreation facilities? What are the maintenance implications? Would painted stripes create a slip hazard?
Section 1103.3 Clear Width - New construction should be able to readily accommodate this provision, but existing ROW and street widths may severely limit the pedestrian path to 32 to 36 inches in width with no possible solution short of total reconstruction of the area which may include removal of street trees, relocation of utilities, etc... Depending on the scope of the project, acquisition of additional Right-of-Way may not be practical, if not technically infeasible.
Section 1103.5 Grade - If landings with no slope to exceed 1:48 are required at the top of ramps, sidewalk slopes adjacent to the landings may have to be warped with a grade temporarily exceeding the street grade. An additional exception may be warranted for this situation.
Section 1188.8.131.52 Cross Slope - Language is too inflexible and may not be able to be consistently achieved given site conditions and construction tolerances for sidewalk concrete work. I would recommend the following language: Maximum recommended cross slope is 1:48.
Section 1184.108.40.206 Landing – Again, language is too inflexible. ROW constraints may prohibit a 48 inch square landing. I would recommend the following language: It is recommended that a landing 48 inches (1220 mm) minimum by 48 inches (1220 mm) minimum be provided at the top of the curb ramp and be permitted to overlap other landings and clear floor or ground space. Running and cross slopes are recommended to be 1:48 maximum.
Section 1220.127.116.11 Flares - For the same reason parallel ramps are not required to exceed 15 feet, an exception not requiring flare lengths to exceed 15 feet should be granted.
Section 1104.2.2 and 1104.2.3 - Parallel Curb Ramps and Blended Transitions - Parallel Curb Ramps and Blended Transitions are highly undesirable on normally crowned streets for reasons of drainage. The landings at the bottoms of the ramps will be prone to flooding. The depressed sidewalk provides a path for storm water flowing in the gutter to leave the ROW and enter private property. The wide flat surface of the landing at the bottom of the ramp allows flow to spread out and slow down dropping any suspended sediment carried in gutter flow onto the landing. These areas will tend to become a muddy hazard to all pedestrians requiring constant maintenance to keep them clear of mud and debris. Shown below is a parallel ramp with a slope flatter than 1:12, because of the sidewalk running slope, but greater than 1:48.
Section 118.104.22.168 Landing - The slope of the landing should match street grade. Any changes in the gutter slope could cause gutter storm water flow to spread into the travel lanes creating a hyroplaning hazard.
Section 122.214.171.124 Landing – I do not understand the exception, particularly for the grade perpendicular to the roadway. Roadway grade should have no effect on the grade perpendicular to the roadway.
Section 1104.3.3 Surfaces – An exception should be given for ramps to be installed at an existing corner. It may be impractical to move all access covers / grates etc… Cost can exceed $100,000 to relocate a major utility vault.
Section 1104.3.6 Counter Slopes - Changing the counter slope or what is in practice the gutter cross slope may have significant impacts on drainage. A sudden flattening of the gutter cross slope will cause the spread of the storm water flowing in the gutter to become wider. If this spread of gutter flow encroaches into the traveled lanes there is potential for hydroplaning which could result in loss of vehicular control. This increased spread effect would be most prevalent where the “counter slope” is changed only in the vicinity of the curb ramp.
Section 1105.2.1 Width – 96 inches is excessive for most crosswalks. A 72 inch wide crosswalk would be adequate at most intersections. The municipality would have the option of specifying a wider crosswalk at higher pedestrian volume crosswalks. In any case, it seems the limiting factor at a crosswalk would be the 48 inch wide curb ramp.
Section 1102.8 Pedestrian Crossings – As the background to the Draft Guidelines states “This specification would require reduction of these profile grades to 2 percent at intersection crosswalks, thus forming “tabled areas” at intersections so that the 1:48 slope is achieved at crosswalks” (underline added). The language in this section is too inflexible. It requires the profile grade to be 2 percent to the exclusion of other considerations.
From a design standpoint, a flatter grade is generally more desirable than a steep slope. This is especially true at intersections where stopping, starting and turning movements occur with great frequency. As I mentioned earlier, however, compromise is often a part of the design process. The implications for grading, vehicular sight distance and many other aspects of design are far reaching.
Groups that would be directly impacted would include adjacent property owners, land developers and tree preservationist. Adjacent property owners would be impacted by significant grading slopes or retaining walls on their properties. In some cases direct access may be lost to adjacent properties. Land developers would face additional grading cost and may be further encouraged to flatten development sites rather than working with the natural contours. The additional grading, away from the natural contour of the land would undoubtedly result in the loss of more trees along roadways.
Less obvious would be the impact on motorist safety and taxpayers in general. Certain generally accepted guidelines apply to roadway grades in relation to how steep grades can be and how quickly grades can change. The guidelines on maximum grades based on the roadway classification and design speed help create roadways on which a controlled stop can be made by vehicles traveling at or below the design speed. There are also guidelines pertaining to how quickly grades change. These help insure there are no humps in the road that would effect vehicular control or obscure sightlines. Clear sightlines allow a hazard to be identified and a controlled stop accomplished when the vehicle is traveling at or below the roadway design speed. The hard and fast requirement for a tabled intersection would often require the designer to compromise on these important safety considerations. That is, if one section of roadway becomes flatter, the approach and departure sections generally become steeper. The constraints of the Draft Guidelines may also dictate that vertical curves outside the generally accepted design criteria be used. This would not allow for safe sightlines. The tabling of the intersection would cause drainage problems. Just as the water from a spilled glass spreads out on a table, storm water flowing in the roadway gutters will spread out at the flattened intersection causing hydroplaning hazards.
These issues will be most difficult to address at existing intersections. If alterations dictate the reconstruction of the intersection grade the costs will be tremendous. Cost for rebuilding an existing arterial roadway run $500 to $600 per linear foot. An existing arterial with a grade of 5 percent through the intersection would require approximately 1500 feet of reconstruction at a cost of over $750,000. If the intersection is signalized $80,000 to $100,000 should be added. This is approaching $1,000,000 even before considering what alterations must be made to the cross street.
Figure 1 shows graphically the changes to the profile grade that would be required in the case given above. Please note that the roadway grade changes by as much as 5.5 feet in this particular example. Not considered in the cost are loss of access and utility relocations.
I would recommend the language in the draft be revised to: It is recommended the cross slope be 1:48 maximum measured perpendicular to the direction of pedestrian travel.
Section 1105.2.3 Running Slope – The 1:20 requirement may be hard to achieve on many older existing streets which have parabolic crowns. It would require completely rebuilding the crosswalk from the subgrade up for some distance either side of the crosswalk. There would also be implications with the storm water gutter flow spreading wider over the flatter street cross section. Again, hydroplanning may become a concern.
Section 1105.3 Pedestrian Signal Phase Timing - Pedestrian timings are covered in the Manual on Uniform Traffic Control Devices. The MUTCD gives the engineer the flexibility to set the timing to accommodate the pedestrians who use the crosswalk, including using walking speeds less than 3 feet per second. The proposed crossing speed will lead to more congestion, air pollution and gas consumption relative to the current accepted standard.
Section 1105.5.3 Approach – The inflexible language requiring an elevator or a lift at every location where grade change exceeds 60 inches will impose significant construction and maintenance cost on the operator. This requirement will have a chilling effect on future construction. The operator should have the ability to make a reasonable decision as to whether or not to install an elevator or lift.
Figure 1: Typical Profile Showing 2% Grade at Intersection
Section 1105.6 Roundabouts – Language in the Draft Guidelines is inflexible lumping low volume traffic circles intended as traffic calming devices and high volume roundabouts together. It seems overly conservative to require pedestrian signals at a traffic circle intended for traffic calming which may have a vehicle pass through it only once every several minutes. Recommendations on roundabouts should be studied further.
Section 1105.6.1 Separation - The same challenges posed by a roundabout are present on large radius intersection corners. The existence of curbs, curb ramps and detectable warnings should provide sufficient cues as to the location of crosswalks. Installation of a continuous barrier is unnecessary.
Section 1105.6.2 Signals – The language of the Draft Guidelines mandates pedestrian signals at all roundabouts. The roundabout shown in the background portion of the Draft Guidelines has crosswalks that appear to be similar to mid-block crossings. If these crosswalks must be signalized, must every mid-block crosswalk be signalized? Must all non-controled crosswalks be signalized? The MUTCD has criteria for the installation of signals. These criteria and engineering judgement should be the basis for installing a signal.
Section 1105.7 Turn Lane at Intersections – My comments for Section 1105.6.2 apply equally to this section.
Section 1106 Accessible Pedestrian Signal Systems - Not all groups agree that audible pedestrian signals are the way to go. Rather than mandating that they be installed, the guidelines should specify what the standard should be when they are used. The guidelines should specify a standard off the shelf system as opposed to a customized systems that can not be readily replaced.
Section 1106.2.1 Location. – Site constraints may preclude total compliance with this section as written. More flexible language would read: It is recommended that pedestrian signal devices be located 60 inches (1525 mm) maximum from the crosswalk line extended, 120 inches (3050 mm) maximum and 30 inches (760 mm) minimum from the curb line, and 120 inches (3050 mm) minimum from other pedestrian signal devices at a crossing. The control face of the signal device should be installed to face the intersection and be parallel to the direction of the crosswalk it serves.
Section 1106.4 Directional Information and Signs - The requirement for ”..tactile and visual signs on the face of the device or its housing or mounting indicating crosswalk direction and the name of the street” will be expensive and difficult to maintain. Tactile street name signs can generally not be fabricated by city personnel and are much more expensive than visual signs. These custom signs will have to be contracted out by municipalities at significant expense.
Section 1108 Detectable Warning Surfaces – Two major problems are posed by detectable warnings. The first is construction. The second is maintenance.
As for construction, no construction tolerances are given. Dome sizes are given very specifically, to the tenth of an inch. Construction tolerances for sidewalk type work allow for considerable variation. Stamped concrete is virtually impossible to hold to very tight tolerances. Precast or other unitized elements that are introduced into the concrete may be difficult to place precisely or settle or react to weathering differently than the concrete sidewalk over time causing level differentials.
Maintenance wise, the domes will cause problems in areas where snow and ice removal is an issue. The question also arises as to how to handle asphalt overlays. Many jurisdictions do not mill out the old asphalt adjacent to the curb, but allow the overlay to continue into the curb ramp to provide a smooth transition to the new paved surface. Obviously, this would cover the detectable warnings rendering them ineffective. The requirement for detectable warnings in effect mandates asphalt milling along the curb lane for some distance from the ramp for considerable added expense.
Section 1109 On-Street Parking – All references to parking should include the word accessible otherwise the guidelines would apply to every parking space. I propose the following wording: On-Street Accessible Parking.
Section 1109 On-Street Parking - This would be a much higher percentage of parking in downtown (short block) areas, as high as one in eight or ten spaces. In some, more suburban, settings it would be a very low percentage. On streets with no marked parking, primarily low traffic residential areas, would accessible parking stalls be required? There may be opposition from residents, “Not in front of my house”. Access Aisles flush with the street would tend to flood and /or hold water and collect silt and debris on normally crowned streets.
Section 1109.1 General – Reword to: Accessible Car and van on-street parking spaces shall comply with 1109.
Section 1109.2 Parallel Parking Spaces – Reword to: Accessible Parallel Parking Spaces.
Section 1109.3 Perpendicular or Angled Parking Spaces - Reword to: Accessible Perpendicular or Angled Parking Spaces.
Section 1109.5 Obstructions – How far from the face of the curb? Does this apply to parking spaces that have access aisles provided? Utility poles, traffic signal poles and light rail catenary poles can cost tens of thousands of dollars to relocate.
Section 1111 Alternate Circulation Path – Clarification is needed in this section. Only after carefully reading this section, Section 1102.3 and the provided background did I begin to understand that this requirement is for the rare situation in which the Pedestrian Access Route is obstructed, but, the remainder of the sidewalk is open. This section provides for equal access to the mobility impaired as required by ADA. In practice the end result will probably be a complete closure of the sidewalk on one side of the street for short duration projects. The alternate circulation path would only be established for long duration projects.
Section 1111.5 Signs – All signs should be in compliance with MUTCD. (See comments Section 1102.7)
Section 1111.6 Barricades - Longitudinally placed rails or barricade elements present a spearing hazard to motorist.
Thank you for the opportunity to comment on the Draft Guidelines at this early point in their development.
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