Dan Wenzel

October 24, 2002

United States Architectural and Transportation Barriers Compliance Board:

I am writing this letter in opposition to the current proposal to mandate the placement of audible traffic signals at all intersections with a walk/don’t walk signal. I also oppose the placement of detectable warnings at every street crossing without exception. I have worked professionally with blind people of all ages (birth-senior citizen) for nearly ten years now. For five of those years I taught travel (Orientation and Mobility) to blind adults and teenagers at the Colorado Center for the Blind. My personal experience as a blind person and my professional experience in working with clients who are blind lead me to the conclusion that in most cases audible traffic signals are unnecessary, and in some cases may even be more of a safety hazard to the pedestrian. Detectable warnings at street crossings are also unnecessary for most intersections, unless the downward slope of the curb, median or island is 1:15 (1 inch for every 15 feet of sidewalk) or less.

A blind person relies on sound cues from the flow of parallel traffic and the idling of perpendicular traffic that has stopped in order to cross a street efficiently and safely. Audible traffic signals should not be installed except on the rare occasion when an intersection has signals, traffic patterns or a layout that makes it impossible for a blind person to use the traffic cues to tell when to cross a street and/or to stay within the designated crosswalk. A vibrotactile indicator should be used instead of an audible traffic signal when such cases arise. The sound emitted from audible traffic signals make it much more difficult for the blind person to monitor traffic patterns. The problem is intensified when you factor in noisy locater tones and add the quieter engines of newer cars to the mix. The addition of these audible traffic signals will only add to the confusion of the blind pedestrian, increasing the difficulty to successfully cross the street.

The masking of traffic cues is not the only problem associated with audible traffic signals. One past example of a travel lesson I taught with students illustrates just how problematic an audible traffic signal can be. While working with two students on crossing intersections in the city of Denver, we came to an audible signal (I believe the signal was at Broadway and Bates). Both students had been in the program for a couple of months, so they had the basic alternative skills of blindness to be able to use traffic to cross a street safely. In this case, the street we were crossing (Broadway) was much busier than the parallel street (Bates), so the students had to rely more heavily on the perpendicular, idling traffic to determine when to cross the intersection. The audible signal did work when the button was pushed, signaling the students and myself that it was time to cross. Unfortunately, the signal masked the sound of the idling traffic, making it extremely difficult to use the stopped traffic as an indicator that it is truly safe to cross the street. A crucial part of safely crossing an intersection for any pedestrian is being able to double-check that traffic has stopped before proceeding across the street. This safety measure was weakened for us as blind pedestrians because of the difficulty we had in hearing traffic cues, and this intersection did not even have a locater tone. The point that audible traffic signals can be confusing was driven home near the end of the lesson as we headed back to the Colorado Center for the Blind. The Center was located just North of Illiff on Broadway at that time. We had some time before class was finished, so I decided to work with the students on this intersection before returning to the Center. On the Northwest corner of Illiff and Broadway was a self-serve hand car wash, which was operated by paying change in order to activate a hose that was used for washing cars. As we stood at the corner listening for traffic cues to tell us when it was safe to cross, we heard a beeping sound that lets people know that the time the hose would squirt water was almost up. The sound that was emitted from this corner car wash was almost exactly the same sound that we had heard at Broadway and Bates earlier in the lesson, causing some confusion and difficulty when trying to use the traffic cues that would enable us to safely cross street. For my money, the safest way to cross almost all intersections is to use the proven method of listening for traffic cues.

The installation of audible traffic signals at the vast majority of lighted intersections and the placement of detectable warnings at most streets will not have a positive impact on the pedestrian population (disabled or otherwise), will not lower the incidence of driver error in pedestrian/motorist accidents and will not make the crossing of most intersections any safer for the blind pedestrian. Unfortunately, the proponents of audible traffic signals and detectable warnings have claimed that it is a safety issue for blind people to not have these audible signals and detectable warnings at intersections. The fact is that such devises will not lower the incidence of driver error in auto/pedestrian accidents, and will not provide blind people with the skills they need to cross intersections safely. The idea that an audible signal will improve safety is not only misleading, but it can provide the sighted public with a negative view of the abilities of blind people to safely travel using alternative techniques. These false perceptions of the abilities of blind people can have a lasting negative impact when blind people attempt to find jobs and participate as equal members in society. The best way to ensure the safety of blind people is to provide them with the skills of blindness needed to safely locate and cross intersections using environmental and traffic cues. Countless successful blind students, professionals and leaders throughout the United States (and the World) employ these techniques to safely travel in all types of conditions without assistance on daily basis.

I strongly urge contacting and working with the National Federation of the Blind when determining possible environmental changes or to learn about the abilities and needs of blind people. Please do not waste time and resources on ineffective and often hazardous audible traffic signals and unneeded detectable warnings. Thank you for taking the time to consider this document.

Dan Wenzel