|October 14, 2002|
I am filing my comments with regard to the Draft Guidelines for Accessible Public Rights of Way of June 17, 2002.
I am a member of the National Federation of the Blind, and support most of the recommendations contained in these guidelines. I am an electronics engineer, and have traveled in many places in the United States, using a long white cane, for forty years. This travel has included fair weather as well as foul, broken-down sidewalks, intermittent sidewalks, multi-lane street crossings, non-controlled street crossings, and much more. In 1992 I was one of the instigators of an NFB resolution that expressed some flexibility regarding the need for audible pedestrian signals. In 2001 I had the privilege of serving on a panel of the Maryland State Highway Administration which developed a set of warrants for the installation of "accessible" pedestrian signals.
I support the construction of more and better sidewalks, and a greatly increased understanding of the needs of pedestrians (particularly those who cannot drive) when vehicle ways and mass transit are being planned, re-purposed, reassessed and constructed.
I would not like to see these guidelines increase the cost of pedestrian accommodations so greatly that pedestrian access projects are not carried out or are postponed due to a lack of funds. I have the feeling that, even though thousands of hours have gone into the process of writing these guidelines, there are still too many proposed requirements that are "nice to have's" without properly delineating the "must-have's" of pedestrian access.
Blended transitions, perpendicular and parallel curb ramps: I am concerned that people are going to make blended transitions between sidewalks and streets the norm. Where is water supposed to drain?
Vehicles can tolerate more water on their paths than pedestrians can. I support the deprecation of "split the difference" curb ramps which dump pedestrians into the intersection instead of into the crosswalk.
If a blended transition is built, and detectable warnings are placed around the corner, in front of both crosswalks, how are blind pedestrians expected to know the direction of these crosswalks. This would seem to be problematic at intersections with little traffic, where the intersection is offset or not at right angles. Remember that most intersections will not have pedestrian signals of any kind installed, due to the lack of traffic.
When a parallel curb ramp is built, dividing a sidewalk into a portion sloping downward toward street level and a part which is not, what sort of "barrier is contemplated between the two adjacent sidewalk segments? A raised row of bricks? A guard-rail? I can't really picture this.
"Accessible" Pedestrian Signals: I have major reservations regarding the usefulness, safety, and consistent application of these devices.
I support the NFB's position on APS's whole-heartedly. But many NFB statements have mistakenly said that a pedestrian signal "informs a pedestrian when it is safe to cross." It does no such thing. It only informs pedestrians that they have an enhanced right of way for a specific period of time, which may or may not be noticed by drivers. Blind people must be enabled to engage in "defensive walking" as much as drivers are encouraged to drive defensively. In developing these standards, we must not forget the phenomenon that people (pedestrians and drivers) can only pay attention to a small number of stimuli at any particular moment. The unexpected event is usually the most dangerous one. I would hypothesize that a tactile stimulus does not compete for attention among audible stimuli as strongly as an audible stimulus does. Knowing when the pedestrian "start walking" interval occurs is important and useful. Knowing what vehicles around you are doing, and walking in the proper direction, is critical.
Many of the comments you are receiving on the guidelines are from people who have never experienced what is being proposed. You see far too many references to "chirping birds" and other sounds which are not proposed. Nobody should be told that these signals are good or bad until they know how they are supposed to work, and they have tried them.
In my opinion, the studies which the Access Board has conducted have involved really small numbers of blind people, and in many cases the work was carried out under artificial conditions, or only in good weather. And in some studies, the opinions and performance of sighted orientation and mobility instructors are counted as just as important as those of the people who will use the equipment--blind people. In the Washington, DC area, as of this writing, I don't think there are ANY intersections containing the proposed types of APS's, whose crosswalks, curb ramps and other pedestrian features comply with the proposed guidelines. Why should anyone be expected to endorse a system when it stands on several unstable legs, and has not been tested as a whole? Why should the Access Board mandate the installation of APS when they are poorly understood by the Americans who need to build and use them? I support further research and limited installations, to address problems such as we identified in our Maryland Highway Administration warrants system. But I believe that mandating "accessible" pedestrian signals across the board, in all cases, is premature, expensive, foolish and dangerous.
Locator tones: These ought to be called "locator clicks" because they ought to be short enough not to have a well-defined pitch. If the locations of these new signals can become standardized, no tones should be necessary. A cane or guide dog can find APS pedestals, if they are in predictable locations. Even though the guideline and the studies state that the sound pressure level at a distance of three feet should be "plus 2 to plus 5 dB" above the ambient sound level, there is no mention of the time constant of the gain control circuit which maintains this level, and where the ambient noise level is measured in order to control the APS's audio output. The investigators have forgotten that these signals, especially the locator tones, could be set several dB below the noise level and still be heard, because the human ear and brain can detect weak signals having specific frequencies and amplitude profiles. If the levels were reduced 5 or more DB below what is proposed, and the time constant for gain control shortened, there would be less tendency to hear "ping-ponging" signals from several APS around one intersection. Researchers and blind people must also decide, once and for all, whether they expect to use these signals as beacons while out in the middle of the street, or not. The new signals seem to be designed to "launch" a person into the intersection at the designated time and in a specific direction, and not to provide a beacon as the pedestrian is approaching the opposite side of the street. That's how I think they should work, but I don't know whether that is the expectation of the people who want to use these signals. And I don't know whether enough research has been done to verify that this concept works well for intersections which are extremely wide and/or extremely complex.
I am not yet confident that traffic engineers and their contractors will be able to install and maintain APS devices. Will shortcuts be taken in the interest of not burying cable, such as wirelessly controlled signals which are occasionally mis-activated or blocked by radio interference? Signals whose timing has gotten out of sync with the visual signal timing, but an inspector didn't notice or didn't know how to properly check? Directional arrows not lined up with the crosswalk for which the device is signaling? Devices mounted to the existing pole for the pedestrian activation button, even though the existing pole is several feet away from the "starting line" which the pedestrian should be on? But speaking of starting lines, I'm happy that the guidelines posit a slower walking speed, and therefore a longer pedestrian clearance interval.
It is often asserted that traffic is becoming quieter, especially with the advent of electric cars and better mufflers. It is true that the difference in noise output at idle between the loudest and quietest vehicles is increasing. Many trucks and buses are getting louder without limit. In other locations, the noise of building ventilation systems can mask much of the traffic noise. This situation, particularly electric cars, deserves somewhat more study.
Clearly, electric cars will make tire noise while they are moving. I might support the concept that such cars be required to emit some noise while stopped and ready to accelerate or turn. In other words, rather than create more noise and put new pedestals on the sidewalks, it may make more sense to insure that motor vehicles are audible, and also that the greatest contributors to noise pollution be muffled.
Detectable Warnings: I think there may be some intersections and islands where truncated domes would be useful. But again I would rather see ramps and curved edges for walkways, which can provide as much information as the domes can. The installation of detectable warnings at all covered intersections seems wasteful and unnecessary, unless "flat" or "raised" intersections are to become the norm.
Thank you for your consideration of all of these comments. I hope that sanity will prevail when these guidelines become a proposed rule.
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