Pedestrian overpasses and underpasses shall comply with 1105.5
Gilmer D. Gaston, P.E., PTOE, August 14, 2002
As a traffic engineering professional, I feel compelled to comment on the Access Board's proposed Draft Guidelines for Accessible Public Rights-of-Way. I formerly managed the traffic signals section for the City of Houston, so I have a feel for how severe these requirements will impact the agencies.
While the guidelines were undoubtedly prepared by a group of well meaning individuals. They contain several items that could have severe and unintended consequences. I have provided a few comments on some of what I feel are the more onerous sections of the document.
1105.3 Pedestrian Signal Phase Timing. All pedestrian signal phase timing shall be calculated using a pedestrian walk speed of 3.0 feet
1105.7 Turn Lanes at Intersections. Where pedestrian crosswalks are provided at right or left turn slip lanes, a pedestrian activated traffic signal complying with 1106 shall be provided for each segment of the pedestrian crosswalk, including at the channelizing island.
Is there actual crash data that supports the need for this measure? We know that there are a lot of pedestrian accidents at intersections; however, it is my understanding that in most of those instances the pedestrian is not using or following the guidance of the existing pedestrian signals. This item would probably put an unnecessary burden on agencies to retrofit existing intersections for little, if any, safety benefits, and a likely decrease in the operational benefits of right-turn lanes.
Something that I didn't see, that I believe could be useful is a recommended maximum distance from the crosswalk for the placement of pedestrian pushbuttons.
The US Congress is known for passing good intended legislation that often results in unintended actions by the public. This leads to more legislation and more requirements as it can produce unintended results. A possible,
unintended consequence of unnecessarily stringent requirements could be a reduction in the number of crosswalks. Some intersection crossings may be signed for no pedestrians because the disbenefits to intersection operations could outweigh providing a crossing that complies with these guidelines.
If you have any questions, or comments, let me know. I may provide additional comments later, as I have a chance to further review these materials.
Gilmer D. Gaston, P.E., PTOE
Sr. Transportation Manager
Pape-Dawson Engineers, Inc.
San Antonio, Texas
Pamela Drake, October 25, 2002
I support the recommendations of the PROWAC report. Pedestrian safety is of the utmost importance to all pedestrians.
Most Sincerely,
Pamela Drake
Scott Batson, P.E., August 12, 2002
Below please find my comments regarding proposed modern roundabout accessibility rules:
1105.6 Roundabouts. Where pedestrian crosswalks and pedestrian facilities are provided at roundabouts, they shall comply with 1105.6.
1105.6.1 Separation. Continuous barriers shall be provided along the street side of the sidewalk where pedestrian crossing is prohibited. Where railings are used, they shall have a bottom rail 15 inches
Comment: The guideline as specified is too broad. No guidance is provided regarding the boundary for where a roundabout intersection begins or ends and thus a barrier begins or ends. The nature of a roundabout intersection is similar to a curved section of roadway or a mid-block crossing. The requirement of a street-side barrier at a roundabout intersection to separate vision impaired pedestrians from the roadway seems arbitrary. The logical extension of such need for barrier would be to install barriers at the edge of every sidewalk which is adjacent to a street. No substantive argument or evidence has been provided that distinguishes a modern roundabout pedestrian crossing as inherently less safe than any other mid-block crossing design or intersection treatment, and thus warranting such barrier. Location of the pedestrian crossing can be accomplished with a depressed landing adjacent to the ramp that directs pedestrians into the marked crossing.
1105.6.2 Signals. A pedestrian activated traffic signal complying with 1106 shall be provided for each segment of the crosswalk, including the splitter island. Signals shall clearly identify which crosswalk segment the signal serves.
Comment: The guideline as specified is too broad. The guideline appears to apply to all sizes and types of roundabouts with pedestrian facilities regardless of the level of auto or pedestrian traffic use. As roundabouts have so many different applications, with a similar variety of pedestrian environments, a single protocol without regard to traffic volume or the number of entry or exit lanes a pedestrian is expected to cross will unduly limit the modern roundabout's application due to the cost of this guideline. This would be unfortunate as modern roundabouts have a clear record of reducing total crashes and crash severity as compared to standard signalized traffic control. I would suggest additional research into the methods used in Australia and Europe, where modern roundabouts are used at high pedestrian use locations with regular frequency.
The guideline singles out the modern roundabout intersection control geometry without a clear argument or evidence of a safety need. The logical extension of this guideline is the need for pedestrian actuated signals at all intersections, regardless of traffic volume.
Scott Batson, P.E.
Senior Engineering Associate
Portland Office of Transportation