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.
Sincerely,
D. W. Vaughn
Assistant Transportation Director
DWV/SEW:sfg
Attachments
Alabama Department of Transportation
Americans with Disabilities Act
Accessibility Guidelines
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 1106.2.3.2 – 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.