Bruce E. Friedman, P.E., PTOE and the NCUTCD Signals Technical Committee
|October 23, 2002|
The attached are the collective comments of the Signals Technical
Committee of the National Committee on Uniform Traffic Control Devices regarding
36 CFR Parts 1190 and 1191 [Docket No. 02-1] as published in the Federal
Register on 6/17/02.
Bruce E. Friedman, P.E., PTOE
Kimley-Horn and Associates, Inc.
Signals Technical Committee
National Committee on Uniform Traffic Control Devices
Memo to: Mr. Scott Windley, U.S. Access Board
From: Signals Technical Committee, NCUTCD
Date: October 23, 2002
Re: Comments on the portions of the June 17, 2002 “ Draft Guidelines for Accessible Public Rights-of-Way” that relate to traffic control signals
The Signals Technical Committee of the National Committee on Uniform Traffic Control Devices has reviewed the above draft guidelines and has the following comments about the portions pertaining to traffic control signals and related items. We compliment the Access Board on tackling a wide array of impediments to the mobility of all citizens, particularly those with disabilities. Our concerns and comments relate to what we believe is a prudent response to these needs.
Section 1105.3 Pedestrian Signal Phase Timing
This section states that all pedestrian phase timing shall be calculated using a maximum pedestrian walking speed of 3.0 feet per second. It also requires that the calculation extend the crosswalk to include the length of any curb ramps. This will result in increased traffic delay and congestion, especially by requiring it at “all” locations, and by including the ramps in the calculation. In coordinated signal systems, cycle lengths will need to be lengthened. The additional delay and congestion will in turn result in an increase in traffic accidents.
We object to this requirement being applied to “all” intersections. Traffic engineers have always used judgment to decide when and where to apply devices, based on an engineering study of need. Where needs are documented, there are many tools available to the traffic engineer to serve populations that require more time to cross the street. If intersections have pedestrian signals that operate pretimed, pushbuttons can be installed to assist those with a need for more time to complete their crossing. If persons who need more time frequent an actuated intersection, longer clearance times can be provided by supplemental actuation, such as pushing and holding the pushbutton to distinguish those calls from ones requiring only routine timing. To require longer pedestrian clearance timing at all traffic control signals (since all signals, even those without pedestrian signals, must provide adequate time for pedestrians to cross a street if pedestrian movements regularly occur) is a total over-reaction to a need that may exist at some locations, but certainly not at all locations. At most locations there will be a price to pay (in the form of a reduced level of service on the arterial, increased congestion, and increased accident rate) with no offsetting benefit.
Likewise, including the curb ramps in the calculation includes the addition of 3 seconds or more of minimum green time at every intersection. Extensive experience has shown that even with the clearance to the middle of the farthest traffic lane, most pedestrians have enough time using the 4 feet per second walking speed. The FHWA, in a Notice of Proposed Amendments to the MUTCD, has proposed extending the clearance point from the middle of the traffic lane to the curb or edge of pavement. This was very controversial because of the same reasons described above. This proposal was supported by the Signals Technical Committee (STC) as a means of improving the safety of all pedestrians, especially those who are the group targeted by these draft guidelines. We also know from experience that most (99%) of the pedestrians could clear safely when the clearance point was the center of the farthest driving lane, but made the change for the other 1% that felt insecure, in the interest of improving the safety of all pedestrians. We recommend that you hold off on your proposed changes until we see the improvement brought about by this change in the MUTCD.
To universally apply these new guidelines, at 100,000 or more signalized intersections, whether needed or not, is, in our opinion, like providing STOP signs or traffic control signals at all intersections regardless of the need.
It would be interesting to know if the 3.0 feet per second walking speed was determined from research results. If yes, would it be possible for you to provide a copy of that research to the Signals Technical Committee?
Section 1105.6.2 Roundabouts – Signals
This section requires a pedestrian activated signal for each crosswalk at a roundabout. The narrative clearly points out that some believe roundabouts should not be used in areas of high pedestrian activity. This is an accurate conclusion, and these new devices have limited application in urban areas because of that. In areas of heavy pedestrian activity, all pedestrians, not just those with disabilities, will have trouble crossing at roundabouts, especially those with multiple-lane approaches. But to require traffic control signals at these crosswalks would be the same as requiring a pedestrian actuated traffic control signal at every marked crosswalk, regardless of the difficulty of crossing, regardless of the amount of pedestrian traffic, and without any study indicating that they would be justified.
Few roundabouts would ever be built under these circumstances if this requirement stands. To discourage the use of an effective tool that can be used to minimize delay and congestion at locations that would otherwise have a higher crash rate is contrary to all sound traffic engineering principles. European roundabouts built to the new modern standards, with funneling to slow traffic, do not add pedestrian signals automatically. If a roundabout is built in the U.S., and pedestrian traffic experiences difficulties, actuated pedestrian signalization may well be justified, but it should not be required on every roundabout where pedestrian traffic of all abilities may not have any problem. The STC is opposed to this recommendation. Roundabouts should only be signalized where a need is shown. Other solutions, such as wider splitter islands or in-roadway warning lights, might be more helpful than signalization for pedestrians. Language pointing out the incompatibility of roundabouts and heavy pedestrian activity should be included.
Section 1105.7 Turn Lanes at Intersections
This section requires a pedestrian actuated traffic signal at right or left turn slip lanes (bypasses) for the crosswalk across these lanes, including the channelizing island. This again requires all situations be treated the same, regardless of need, and is counter to all traffic engineering principles that required study and justification for the installation of traffic control devices. The fact that these signals would seldom be actuated and drivers would not expect a red light at these locations does not create a safe situation for such crosswalks. Furthermore, these channelized lanes are typically 15 feet or less in width and most pedestrians would not be patient enough to wait for the WALK signal to cross.
There is an implication in these guidelines that somehow traffic control signals will improve safety and accessibility for all when applied. Traffic engineers know this is not true, and that often the opposite occurs. Proliferation of devices breeds disrespect and wastes resources that could better be used to provide facilities where the need is greater. The STC is opposed to this recommendation, and believes that it is not well-founded.
Section 1106 (and 1102.8) Accessible Pedestrian Signal Systems
The STC has been working with representatives of the blind community and mobility education specialists, as well as representatives of the US Access Board, on this for more than three years. Some language has been put into the MUTCD already. We have standardized certain functions of Accessible Pedestrian Signals (APS) where we know or want to shape good practice. What we do not yet know is how to standardize on these devices. We are aware that the Access Board has pioneered work on a synthesis of current technology. We know some of the current technologies are not effective or lack in certain features that we believe to be important. For that reason the NCUTCD has requested funding for research to answer the questions of effectiveness. We do not want to see a proliferation of such devices until the research is completed. The Transportation Research Board, under its National Cooperative Highway Research Program (NCHRP) has launched a comprehensive study to obtain this information. We are probably about 24 months away from implementing these results. In addition, the National Institute of Health has research underway that will complement that of the NCHRP. Two members of the STC serve on the NCHRP panel to ensure that the research provides the traffic engineering profession with the information we need to adopt standards governing the installation and operation of APS. The two research teams have overlapping membership, so we are confident that we can continue to work with members of the Access Board and the blind community to improve mobility. We have to deal with issues of where and under what conditions they will be installed. Perhaps a way to start is to standardize all pedestrian pushbutton locations for all traffic signals, and our STC task force is working on that. But it is premature and not in the public interest to adopt the guidelines now until such research is completed. Even the standardization of the location of APS is not yet answered, and to spell out exact locations for them as proposed in Section 1106.2.1 is premature, and may not be the correct location for certain complex intersections. The above mentioned research is also addressing that.
Section 1106.3 Pedestrian Pushbuttons
This matter is still being studied by the STC and we request a delay until we can obtain input from the research mentioned above. We agree that there needs to be more standardization of pushbutton locations, recognizing that corner radius geometry sometimes limits the options, and we hope to have all typical conditions covered. Certainly, prescribing the location of pushbuttons needs to take into account the minimum clear width also required, and this may be more important than meeting the exact requirements of the dimensions shown for pushbutton locations. We also need to find out more about locator tones before we can standardize on their sound levels and aiming.
In conclusion, we believe the Access Board is making progress in implementing the requirements of ADA. We are willing to work with all the stakeholders to help, but are concerned with "across-the-board" requirements that are unrealistic to achieve. Specifically, a 3.0 feet per second walking speed for pedestrian clearance intervals is not feasible at all locations. Requiring signals at all roundabouts has not proven to be justified. Signalizing turn lanes at channelizing islands can create new safety issues. In addition, we believe that implementation of the requirements of Section 1106 should wait until the ongoing research is completed. This research will answer many of the questions we have and will help us implement the draft guidelines into the MUTCD.
Another important consideration is that the Access Board needs to recognize that agencies responsible for the installation of traffic control devices have limited resources. The requirements for Accessible Pedestrian Signals at all locations should not be applied universally, at the time of reconstruction or alteration, without prioritizing needs. We believe this will not be in the best interests of the very community that is being served by these new guidelines. Traffic engineers can evaluate and prioritize needs, with help from the affected community, as now provided for in the MUTCD. These guidelines ought to support that direction. To do less would not serve the community with disabilities.
Thank you on behalf of all of the members of the STC for your consideration of our collective comments.
Bruce E. Friedman, P.E., PTOE
Signals Technical Committee of the NCUTCD
cc: STC members
Sent in via e-mail by:
Bruce E. Friedman, P.E., PTOE
Kimley-Horn and Associates, Inc.
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