Illinois Department of Transportation
|
October 28, 2002 |
BUREAU OF DESIGN AND ENVIRONMENT COMMENTS ON
DRAFT GUIDELINES FOR ACCESSIBLE PUBLIC RIGHTS-OF-WAY
The Department of Illinois has reviewed and is in agreement with the
response provided by AASHTO and provides the
additional comments.
Section 1101.2.1 – Referenced Standards, MUTCD
Many of the guidelines supercede or conflict with those in the MUTCD, and for
what may be arbitrary causes. If this cannot be avoided, the rational basis for
the conflicts should be presented. If the arguments are convincing, the MUTCD
should be updated to reflect the changes when accessibility concerns are
present.
Section 1101.3 – Defined Terms
The term “blended transition” is used throughout the guidelines, but is never
adequately defined. An internet search also yielded no useful definition of the
term. Its clear definition should be included in this section. An illustrative
figure would also be helpful.
Section 1102.2.2– Alterations
Exception:
The guidelines state that if an alteration with an applicable provision is
technically infeasible, the alteration shall comply to the maximum extent
feasible. There is not any criteria provided listing what is considered
infeasible and who decides and approves what is infeasible. Existing features
and limited right-of-way widths could be considered as reasons not to comply
with the guidelines. In addition, local communities may coordinate with their
disability organizations to better address their constituents’ needs. This may
call for variances to these guidelines. Are there any allowances for this?
Section 1102.2.2.2 –Prohibited Reduction in Access
This does not recognize that an accessible route may already be below the
requirements new construction.
Section 1102.3 – Scoping Requirements, Alternate Circulation Path
Even if technically feasible, it is not always desirable to provide such an
alternate route – particularly along a project’s entire length. In some
instances, the project scope and conditions on the ground are such that users
cannot or should not be accommodated along the route to be improved for the
users’ own safety. Individual jurisdictions should have the flexibility to
choose not to provide the alternate path, in consultation with a locality’s
disabled community.
Section 1102.5.3- Reduced Vertical Clearance
Define “leading edge” or use better terminology such as “the top” or “the
bottom” of guardrail or barrier.
Section 1102.14 – Scoping Requirements, On-Street Parking
The requirement of at least one accessible on-street parking space per block
face where on-street parking is provided is arbitrary. This does not consider
block length, land use type, density and other pertinent issues. Further, is
there a rational basis to believe there is sufficient demand for these spaces?
Individual jurisdictions should have the flexibility to craft solutions in
consultation with a locality’s disabled community.
There should be a maximum distance between accessible parking spaces to keep
travel distance for the disabled to a reasonable level. Based on 1 space per 25
spaces, that would come to about a maximum distance of 660 feet. This somewhat
coincides with an informal concept of a city block, about 1/8 mile, and would
match roughly to 1 space per 25 where there is continuous on-street parking.
Section 1103.3 – Clear Width
The minimum clear width of 48 inches is an increase from the current IDOT
minimum of 36 inches at restrictions. While we do normally provide a clear width
of 60 inches, there should be an exception allowed for spot restrictions to 36
inches, such as clearance around utility poles in restrictive right of way.
Section 1104.2 – Curb Ramps and Blended Transitions, Types
What about skewed ramps? Often, the optimal ramp solution is neither parallel
nor perpendicular. Again, this appears to be an arbitrary mandate. It would be
preferable to allow local jurisdictions the flexibility to craft solutions in
consultation with their disabled community.
Section 1104.2.1.1 - Curb Ramps and Blended Transitions, Types, Perpendicular
Curb Ramps,
Running Slope
What is the origin of the specified 1:48 minimum running slope? What is the
purpose for specifying a minimum slope, in any event – drainage?
Section 1104.2.2.1 – Curb Ramps and Blended Transitions, Types, Parallel Curb
Ramps,
Running Slopes
SAME AS DIRECTLY ABOVE.
Section 1104.3.3 - Surfaces
This criteria does not recognize and allow for gratings and access covers and
other appurtenances that may already exist in curb ramps, landings, blended
transitions, and gutter areas within the pedestrian access. Moving these
appurtenances may hinder future maintenance of such items, and significantly
complicate drainage and utility design and construction at increased cost.
Section 1104.3.6 – Curb Ramps and Blended Transitions, Common Elements, Counter
Slopes
What is the origin of the 1:20 maximum ramp counter slopes? This conflicts with
state policy gutter pan slopes (6%), necessary for proper drainage. It could
also cause problems in areas of superelevated highway pavement, the slopes of
which can be up to 8%.
Section 1105.2.1 - Pedestrian Crossings, Crosswalks, Width
The minimum width is another conflict with MUTCD. What are its origin and
justification? If it cannot be avoided, a rational basis for it should be
presented. If the basis is valid, the MUTCD should be updated to reflect the
changes in areas where there are accessibility concerns.
Section 1105.2.2 – Pedestrian Crossings, Crosswalks, Cross Slope
What is the origin and justification for the 1:48 maximum cross slope? This
could greatly complicate intersection design and construction in accessible
areas and considerably compromise vehicle ride on the highway facility.
Section 1105.2.3 – Pedestrian Crossings, Crosswalks, Running Slope
What is the origin for the maximum running slope of 1:20? It will be impractical
and unsafe in areas of superelevated highway pavement.
Section 1105.3 – Pedestrian Crossings, Pedestrian Signal Phase Timing
What is the origin and justification for the choice of pedestrian walk speed of
3 feet per second? MUTCD calls for 4 feet per second for design. Again, any
departure from MUTCD should be supported by rational evidence – at which time
the manual should be updated. Individual jurisdictions should have the
flexibility to craft solutions for individual locations in consultation with the
local disabled community.
Section 1105.4.1 – Pedestrian Crossings, Medians and Pedestrian Refuge Islands,
Length
What is the origin of the 72 inch minimum cut-through length? Why is it not 48
inches?
48 inches is what is required for landing areas.
What is the proposed minimum crossing width?
Increasing the minimum length of cut-through in medians from 48” to 72” could be
a sole cause for widening. Added width for a median at an intersection would
move out the lanes and require associated lane shift tapers. These changes would
require removal and replacement of existing curb and gutter, widening, and
possibly new right of way, along with new sidewalk in the intersection area.
This one change then snowballs into a major intersection modification. This
would greatly increase design and construction complexity and cost.”
Section 1105.5.3 Pedestrian Overpasses and Underpasses-Approach
Is the 60 inches in total for a route or a portion thereof? The requirement for
an elevator where the rise of a ramped approach exceeds 60 inches seems
excessive for a low volume pedestrian route. This guideline does not
differentiate between a highly urbanized area with significant pedestrian
traffic and a small town with little pedestrian traffic. In addition, if the
elevator is unavailable for use due to malfunction, repair, etc. is an alternate
accessible route required based on Section 1102.3 of the guidelines?
Section 1105.6.1 – Pedestrian Crossings, Roundabouts, Separation
The requirement for barriers at roundabouts is inconsistent with the treatments
used at other locations where pedestrians are prohibited. Positive guidance
principles used elsewhere should also be sufficient at roundabouts.
Section 1105.6.2- Pedestrian Crossings, Roundabouts, Signals
The requirement of pedestrian signals at all crosswalks is arbitrary, and
potentially onerous. Is there a rational basis to believe there is sufficient
demand to justify the signal installations? The potential negative safety and
operational impacts on the facility are considerable. Individual jurisdictions
should have the flexibility to craft solutions for individual locations in
consultation with the local disabled community.
Section 1105.7 – Pedestrian Crossings, Turn Lanes at Intersections
Does this apply to true “slip lanes” where a lane entirely bypasses an
intersection, or does it also refer to all turning roadways at intersections?
Pertinent literature would seem to indicate it applies mostly to turning
roadways. Many of these exist at unsignalized intersections. Is there a rational
basis to believe there is sufficient demand to justify these installations? The
addition of a signal at each of these locations could have a deleterious effect
on vehicular safety and operations. It would also be quite expensive..
Individual jurisdictions should have the flexibility to craft solutions for
individual locations in consultation with the local disabled community.
Section 1106.2.1 – Accessible Pedestrian Signal Systems, Pedestrian Signal
Devices, Location
What are the origins and justifications for the dimensions shown? In areas where
a boulevard two feet (2’) in width exists, meeting the 30” width would not be
possible. Individual jurisdictions should have the flexibility to craft
solutions for individual locations in consultation with the local disabled
community. This guideline does not account for existing accessible routes.
Section 1108.1 – Detectable Warning Surfaces, General
The difficulty of properly clearing these surfaces in snow and ice conditions
will render them useless to those they are intended to assist, and will pose
undue hazards for all users in such conditions. Allowances should be made for
local agencies to continue to coordinate with their disabled population to
construct a warning surface pattern that meets the needs of their constituents.
Section 1111.3 – Alternate Circulation Plan, Location
Even if technically feasible, it is not always desirable to provide such an
alternate route – particularly along a project’s entire length and on the same
side as the existing route. In some instances, the project scope and
conditions(i.e., the operation of large equipment) on the ground are such that
all users cannot or should not be accommodated along the route to be improved
for the users’ own safety. Individual jurisdictions should have the flexibility
to choose not to provide the alternate path, in consultation with a locality’s
disabled community.
General
A consistent theme of these draft “guidelines” is to establish arbitrary
requirements for accessible facilities. This document is very rigid and does not
allow for varied degrees of pedestrian use. For this document to serve its
intended purpose, any technical requirements therein must be rigorously
justified and documented. There must also be rational bases to indicate the need
for a specific requirements included therein. There also must be intrinsic
flexibility within the guidelines allowing each individual jurisdiction the
freedom to create optimal solutions considering all pertinent factors on the
ground.
Highway design is currently experiencing a revolution with a concept known as
“Context Sensitive Design”, the thrust of which is to tailor designs to the
context of their location and users. It seems incongruous to develop
accessibility guidelines which are in diametric opposition to this notion, and
which cannot result in the best designs obtainable.
There should be a complete set of drawings to depict the various design criteria
and concepts.
Comments for AASHTO
IDOT welcomes and endorses the AASHTO comments and
recommendations relative to the “Draft Guidelines for Accessible Public
Rights-of-Way,” with a few added comments as follows:
1101.2.1 – Referenced Standards, MUTCD.
Many of the guidelines supercede or conflict with those in the MUTCD, and for
what may be arbitrary causes. If this cannot be avoided, the rational basis for
the conflicts should be presented. If the arguments are convincing, the MUTCD
should be updated to reflect the changes when accessibility concerns are
present.
1101.03 – Defined Terms
The term “blended transition” is used throughout the guidelines, but is never
adequately defined. An internet search also yielded no useful definition of the
term. Its clear definition should be included in this section. An illustrative
figure would also be helpful
1102.2.2.2 – Prohibited Reduction in Access
This does not recognize that an accessible route may already be below the
requirements new construction. Under AASHTO’s recommendation # 2, reference is
made to set a maximum cost based on a percentage of the highway construction
project. Something being technically feasible or not is not just a cost issue
but an impact to the project and also the surrounding area. What about varied
degrees of pedestrian traffic? This is not mentioned as a consideration for
application of these guidelines. It is a “one size fits all” application.
1102.3-Alternate Circulation Paths
1111.3-Location (of Alternate Circulation Paths)
AASHTO’s recommendation of a minimum time period is a step in the right
direction. However, a period of 24 hours or greater or overnight closures is
suggested by AASHTO. Should this period either be extended or specific types of
operation (work) be permitted without closure, i.e. constructing curb ramps at
intersections?
1104.2.1.1 and 1104.2.2.1 – Curb Ramps and Blended Transitions, Types,
Perpendicular Curb Ramps, Running Slope AND Curb Ramps and Blended Transitions,
Types, Parallel Curb Ramps, Running Slopes
What is the origin of the specified 1:48 minimum running slope? What is the
purpose for specifying a minimum slope, in any event – drainage?
1105.4.1 – Pedestrian Crossings, Medians and Pedestrian Refuge Islands. Length
The minimum width is another conflict with MUTCD. What are its origin and
justification? If it cannot be avoided, a rational basis for it should be
presented. If the basis is valid, the MUTCD should be updated to reflect the
changes in areas where there are accessibility concerns. Increasing the minimum
length of cut-through in medians from 48” to 72” could be a sole cause for
widening. Added width for a median at an intersection would move out the through
lanes and require associated lane shift tapers. These changes would require
removal and replacement of existing curb and gutter, widening, and possibly new
right of way, along with new sidewalk in the intersection area. This one change
then snowballs into a major intersection modification. This would greatly
increase design and construction complexity and cost.
1108.1 – Detectable Warning Surfaces, General.
The difficulty of properly clearing these surfaces in snow and ice conditions
will render them useless to those they are intended to assist, and will pose
undue hazards for all users in such conditions. Allowances should be made for
local agencies to continue to coordinate with their disabled population to
construct a warning surface pattern that meets the needs of their constituents.
General
There needs to be flexibility throughout for transportation agencies to work
with local communities to develop solutions that are consistent with local
plans.
A full set of illustrations is needed to portray the many numerical criteria and
varied designs.
Levels of pedestrian traffic should be considered as a warrant for varied
degrees of the application of these guidelines.