index previous comment next comment

Comment on Draft Guidelines for Accessible Public Rights-of-Way, published in the Federal Register, 17 June 2002.

As a pedestrian safety analyst, I support the goals of this effort, but share the concerns expressed by others (e.g., AASHTO) that in some sections, the draft guidelines propose inflexible, "Gordian knot" criteria to the application of pedestrian crossing features that are more appropriately and effectively evaluated through the application of engineering judgment, in the light of the "Manual on Uniform Traffic Control Devices" and other engineering guidance documents.

Specifically, I am concerned about the following.

S. 1105.3 would require calculation of pedestrian signal phase timing using a pedestrian walking speed of 3.0 ft per second. Use of such a speed is certainly appropriate in some locations, as recognized by the MUTCD, but blanket application would cause unnecessary delays at many crossings. Delays that are not perceived to be justified may increase the reluctance of drivers to yield to pedestrians in crosswalks.

S. 1105.5.3 would require installation of elevators where the rise of a ramped approach exceeds 60 inches. This would be quite expensive and the elevators would require careful monitoring and maintenance. Many people have security concerns about using outdoor elevators. Adoption of this requirement would likely limit installation of new pedestrian facilities at locations where they are not currently present. Guidelines for use of elevators can and should be described in best practices documents.

S. 1105.6.2 would require provision of a pedestrian activated signal at each segment of a roundabout crosswalk. Although pedestrians often expect they will have difficulty using such crosswalks, prior to construction, I have never heard of any pedestrian request for a signal at a signal-lane roundabout, after it has opened. Adoption of this requirement could result in a reduction of the use of marked crosswalks at roundabouts. I concur with AASHTO that this section should be reserved, pending completion of NCHRP Project 3-65, "Applying Roundabouts in the United States."

S. 1105.7 would required provision of a pedestrian activated signal where crosswalks are provided at right or left turn slip lanes. The problem is that, if the slip lane is designed to facilitate a high speed turn, and the signal is used infrequently, it will be ineffective; many drivers simply fail to heed signal indications they are not used to seeing. The failure of drivers to yield to pedestrians in slip lane crosswalks is better addressed through design, e.g., greater use of high-entry-angle slip lanes such as those used in Australia (cf. the Austroads "Guide to Traffic Engineering Practice," Part 5). Let us hope that NCHRP Project 3-72, "Lane Widths, Channelized Right Turns, and Right Turn Deceleration Lanes in Urban and Suburban Areas," will produce some useful recommendations for the pedestrian crossing problem at slip lanes.

S. 1106 would require all pedestrian signal systems to use audible and vibrotactile indications. In Florida, there have been differences among visually impaired pedestrians as to the usefulness of audible signal systems. Some blind persons believe these features are unnecessary, or create a false sense of security, or make it difficult to hear traffic (at least, if not installed properly). They must also be maintained. It is probably better to continue with the current practice of considering installation of such systems on request.

I also concur with AASHTO that the hard conversion of dimensions stated in US customary units into their SI equivalents lends itself to impractical inferences with respect to tolerances. Metric tolerances need to be clarified.

Dwight Kingsbury, Ph.D.