D. W. Vaughn
|October 25, 2002|
Alabama Department of Transportation
Attached are comments from the Alabama Department of
Transportation regarding the Draft Guidelines for Accessible Public
Right-of-Way. We support the comments from the
American Association of State Highway and Transportation Officials (AASHTO). We
provide these comments to highlight areas of specific concern for our agency and
its use of limited highway funding resources.
Please consider these comments as you evaluate the content of the guidelines.
D. W. Vaughn
Assistant Transportation Director
Alabama Department of Transportation
Americans with Disabilities Act
The following comments are offered regarding the proposed accessibility guidelines:
1. Section 1102 – Scoping Requirements
a. Section 1102.1 – New Construction – The wording in this section could have a wider application than intended and it could be interpreted as applying to resurfacing and minor safety projects or similar. A definition of the intended application is needed so that it is clear this applies to new construction and major reconstruction with substantial horizontal and vertical alignment revisions and right-of-way acquisition.
b. Section 1102.2 – Additions and Alterations – There is an exception for technical feasibility. An equally important exception is needed for fiscal feasibility. ALDOT strongly disagrees with the concept of acquiring right-of-way solely for the purpose of providing ADA compliant facilities during alteration type projects. Each DOT should be allowed to determine feasibility in coordination with the Federal Highway Administration.
2. Section 1105 – Pedestrian Crossings
a. Section 1105.2.1 – Width – The required 96-inch minimum width for marked crosswalks is excessive. This allows the passing of 2 pedestrians needing a 4-foot width. The probability of two disabled pedestrians passing in a crosswalk at most intersections is far too low for this to be the national standard. The 96-inch width could be the requirement in high pedestrian volume locations, but the standard 72-inch width should be allowed in most crossings. Allow engineering judgment.
b. Section 1105.2.2 – Cross Slope – The maximum cross slope of a crosswalk at an intersection is limited to 2 percent. This requires the adjacent roadway grade to be 2 percent at the crosswalk. This is extremely impractical. The length required to accomplish this and maintain minimum AASHTO stopping sight distance for vertical curves is extreme. For example, given a road on a 5-percent grade with a 40-mph design speed, the length required to accomplish the grade alterations to a 2-percent crosswalk grade and then return to the 5-percent grade is approximately 800 feet. This grade in itself is very undesirable, but if in a typical urban 660-foot block spacing, the required distances overlap. Attached is a figure showing the required grade to accomplish this for the given scenario. This is not sound engineering.
c. Section 1105.2.3 – Running Slope – The running slope or "grade" of the crosswalk is limited to 5 percent maximum. In most cases this can be met without much problem. However, in some situations the roadway superelevation will exceed 5 percent. For safety purposes, the superelevation of the roadway must govern. The guidelines allow the sidewalk to be set on a grade as steep as the roadway so that pedestrians in a crosswalk may well have traversed much steeper than 5 percent grades approaching the crosswalk. A 5 percent maximum limitation on the crosswalk is impractical.
d. Section 1105.3 – Pedestrian Signal Phase Timing – The draft guidelines would require pedestrian signal phase timing be calculated at the walking speed of 3.0 ft./sec. Recommendation: 3.5 ft/sec. usage. Minute percentage of pedestrians accommodated by 3.0 ft./sec. and not 3.5 ft./sec. does not justify the amount of loss time sustained by all roadway users. The Uniform Vehicle Code requires motorists to yield to pedestrians who are within the crosswalk even though any associated pedestrian phase has expired.
e. Section 1105.5.3 – Pedestrian Overpasses and Underpasses Approach – The guidelines state that where the rise of a ramped approach exceeds 60 inches, an elevator shall be provided. For many pedestrian overpasses, the grade change is in the 20-foot range to achieve superstructure clearance over the roadway. However, if elevators are required, no pedestrian overpasses will be built due to maintenance and liability. This is not practical. Regular ramp requirements should be the governing standard.
f. Section 1105.6 – Roundabouts – The new guidelines require signals at each crosswalk that negate the advantages of having a roundabout. Mid-block crossings also have some of the same needs for a signal, yet they are not required.
g. Section 1107.7 – Turn Lanes at Intersections – The guideline requires a pedestrian activated traffic signal for a free flow right turn lane at an intersection regardless of whether the intersection itself is signalized. This is not practical and will result in few of these turn lanes being constructed. There are numerous such lanes often conceived as a traffic improvement technique to eliminate signals. Installing signals would likely increase congestion.
3. Section 1106 – Accessible Pedestrian Signal System
Situations exists where 1106.2.1 – Location cannot be accommodated; provisions should be made to locate the signal devices as near to the crosswalk alignment as practical.
Other items such as 1188.8.131.52 – Volume, 1106.3.2 – Locator Tone, and 1106.4 – Directional Information and Signs should not be mandatory for every pedestrian signal installation. Engineering study, community input, and budgetary constraints should be included in the process.
4. Section 1111 – Alternate Circulation Path
a. 1111.3 – Location – On construction projects where previous pedestrian access was allowed, the guideline requires an alternate circulation path parallel to and on the same side as the disrupted route. This is an impractical requirement because there are many construction scenarios where pedestrian access on the same side cannot be maintained. The guide should allow properly signed and signalized detour routes that are the most expedient for pedestrian traffic even if crossing to the other side is required.
b. 1111.6 – Barricades – Along the detour, the guidelines require continuous stable, non-flexible barricades. There are many flexible construction fencing products that can be made stable that should be allowed.
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