Pedestrian crossings shall comply with 1105
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
Comments to: Draft of Recommendations of The Access Board on Pedestrian Crosswalks At Roundabouts
Dear Committee Members:
I am since ten years a professor of transportation engineering in the United States. My training was in Sweden where I in 1982 presented my Ph.D.-thesis on Pedestrian Safety at Signalized Intersections. I have worked on research relating to pedestrian safety for 25+ years and parallel to this on roundabout safety for 20+ years and would like to give some comments to your proposed guidelines.
It seems like you write that wherever marked (and possibly unmarked) pedestrian crosswalks are provided at roundabouts, each shall meet the requirements set forth in this section, including: (C) Signals. A pedestrian actuated traffic signal complying with Section ? shall be provided for each segment of the crosswalk, including at the splitter island. Signals shall clearly identify which crosswalk segment the signal serves.
I will comment on this below, in connection to some direct comments to your discussion section. But first, inhttp://www.access-board.gov/rowdraft.htm#1106 you write, "Requiring the signal to be pedestrian activated may help limit the impact on traffic flow." In reality this may be true, but shouldn't the responsibility of lawmakers include that the code be made to be followed? Through education and/or enforcement activities if necessary? As far as I know, pedestrians, in all U.S. states, have the right-of-way in unsignalized marked crosswalks. In other words, the primary purpose of signalizing marked crosswalks should be to give automobile drivers the right-of-way part of the time so that automobile capacity does not become too low where pedestrian flows are high. In Germany, and some other European countries, this is clearly understood and given as the primary reason for signalizing crosswalks. Still, I acknowledge that we in the U.S. live in a country were many drivers do not stop for pedestrians in crosswalks, even for those carrying white canes, and I understand that we may have to 'accommodate' such illegal behavior, and have designs that make it reasonably safe for all pedestrians, including those in wheelchair or visually impaired, even when divers violate codes.
In Discussion (http://www.access-board.gov/prowac/commrept/part3-02-5.htm) you write:
"Modern roundabouts are ?. While this traffic pattern has been an asset to traffic planners in controlling and slowing the flow of traffic at intersections in lieu of having a signalized intersection, the absence of stopped traffic presents a major problem for blind and visually impaired pedestrians when crossing."
I would like that statement to be backed by facts in the form of crash statistics. If it were (only) a perceived "major problem" rather than an actual problem, then maybe education rather than engineering changes would be motivated. I do know that the 'sole' serious opposition to roundabouts in Sweden today stems from visually impaired people and their advocacy groups, and I do not mean that this is not a very important subgroup of the pedestrian population, but still, sub-optimization of our traffic environment is one of the reasons that the risk of fatality per mile walked is about ten times higher in the United States than in Sweden, where roundabouts are utilized frequently in the urban environment. I also know that signalized crosswalks or grade-separated passages are considered at roundabouts in Sweden, where there is a high demand by visually impaired pedestrians? But, to require signalization of all roundabouts is, in my opinion, definitely unwarranted. At least, it is my opinion, that all crosswalk locations away from roundabouts should be signalized prior to the ones adjacent to single-lane roundabouts getting this type of control.
Rather, you should consider requiring signalization of marked crosswalks (or grade-separated crossings) at multi-lane locations including at multi-lane roundabouts with high pedestrian volumes. I am fairly convinced that there is no crash data from the U.S. supporting the view that pedestrians are vulnerable to crashes at single-lane roundabouts. The only pedestrian crash at a U.S. roundabout was, as far as I know, the elderly person hit in Montpelier, VT, and that did not cause any serious injury. Rather, the roundabout prevented the injury. There is statistics from Sweden, showing that 'all' the country's (»700) single-lane roundabouts had a total of three pedestrian crashes (with not a single serious injury) in the 1994 to 1997 period. (Today there are a lot more roundabouts in Sweden, but I do not have any newer statistics.) If these locations had been signalized, there would have been at least 11 pedestrian crashes according to standard models. However, the two-lane roundabouts studied, had an actual safety very similar to signalized locations (10.4 predicted and 12 occurred at the 14 locations in Sweden that have considerable pedestrian traffic.)
You write: "Barriers or similarly distinct elements are needed to prevent blind persons from inadvertently crossing a roundabout roadway in an unsafe location. ? Because the pedestrian crosswalk is generally placed at least one car length from the entry point, in a location that is not immediately apparent to a blind or visually impaired pedestrian, a cue is needed for crosswalk location."
Again, I have no objection to the idea that pedestrians are guided to safe crossing points, but crossing outside the crosswalk at a roundabout is probably safer than crossing anywhere away from a roundabout, so there should be million of miles of barriers put up prior to the ones at roundabouts.
You write, "Pedestrians report that vehicles at roundabouts, right slip lanes, and other unsignalized pedestrian crosswalks often do not yield for pedestrians. Pedestrians with disabilities are particularly vulnerable in these situations. People who are blind or visually impaired are unable to make eye contact with drivers making it impossible to 'claim the intersection.' The driver's view of people using wheelchairs is often blocked by other vehicles. Pedestrians with slower than normal mobility may hesitate when entering the street. All of these situations may result in drivers misinterpreting the pedestrian's intention to cross."
I agree, but this is even truer away from roundabouts at non-signalized locations.
You write, "It is recognized, however, that the purpose of these types of unsignalized crosswalks is to keep traffic moving as continuously as possible."
That is one reason for constructing roundabouts, but I have for over a decade advocated the use of roundabouts for the primary purpose of improving pedestrian safety. That delays are reduces is a side effect rather than the primary purpose in my way of thinking.
You write, "Traffic flow can be achieved, while still affording pedestrians with disabilities the opportunity to cross safely, with the use of pedestrian actuated technologies that halt traffic only while the pedestrian is in the crosswalk. An advantage of passive detectors is that, when pedestrians cross slowly, more time can be automatically provided. When a pedestrian crosses quickly, the traffic is stopped only during the time the pedestrian is crossing, thereby eliminating the problem of traffic being held up when no pedestrian is in the crosswalk."
I agree fully with this strategy. Wherever it is economically feasible, I support the use of passive or active detection and stoplights. But, again, roundabouts should not be the first place to implement such systems.
I recently studied the safety of pedestrians at over a hundred locations in Maine. I counted pedestrian and vehicle volumes and predicted how many crashes there ought to have been if the layout was 'typical' (according to TRL models from England and VTI models from Sweden, which in parenthesis gave very similar results) and compared these estimates to actual crash experience involving pedestrians. I found that the risk of a pedestrian collision is
- roughly 25 times the 'average' where pedestrians cross multi-lane streets at unmarked locations with 25 mph speed limits but actual speeds around 30 to 40 mph
- roughly 10 times the 'average' where pedestrians cross multi-lane streets in marked crosswalks with 25 mph speed limits but actual speeds around 30 to 40 mph
- roughly 4 times the 'average' where pedestrians cross multi-lane streets at unmarked locations with 25 mph speed limits but actual speeds around 25 mph
- roughly 2.5 times the 'average' where pedestrians cross multi-lane streets in marked crosswalks with 25 mph speed limits but actual speeds around 25 mph
- signalization of the above listed locations reduces the risks by roughly 50%
- roughly half the 'average' where pedestrians cross 2-lane streets as an average for all speeds if the street is posted as 25 mph
- extremely low risk where pedestrians cross 2-lane streets in marked or unmarked crosswalks with 25 mph speed limits but actual speeds around 20 mph
There were no multi-lane streets with actual speeds below 25 mph.
All the figures above include visually impaired people but are not specifically true for that group by itself. In summary, 4- and 6-lane streets are very dangerous where speeds are high. Signalization reduces the risk, but the risk is still much higher than at a narrow low-speed location, especially since many of the crashes still occur at very high speeds (jaywalkers or drivers running red lights account for over 50% of the pedestrian crashes). For example, the risk of a pedestrian collision is about 5 to 12 times higher than 'average' at a signalized 4-lane crosswalk if cars are driven at 30 mph whereas it is maybe 20% of the average in the vicinity of a single-lane roundabout (2-lane street) handling the same traffic volume. That is a difference of roughly 50 times. And that is risk of collision, not risk of serious injury or fatality. The risk of fatality, for Maine streets and roads, vary as seen in the table here. In other words, the roundabout may be more than 50 times safer than the signalization.
Table 1 Speed limit and crash severity, Maine data
In conclusion to my comments. I may be wrong in my assessment that non-signalized crosswalks adjacent to roundabouts are very safe for visually impaired people. And I do not want to advocate accepting collateral damage. But, if the design procedures suggested here means that roundabouts will not be constructed, and this means that we will 'keep' signalization and see 500 additional pedestrian fatalities a year compared to if roundabouts were utilized, which would have led to (annually) one visually impaired person being killed at a roundabout, should we then celebrate the saving of that one life at a cost of 500? Maybe? But, what if I am correct, and there will not be any additional deaths among visually impaired people, and the result of this practice will be 500 more pedestrian fatalities and not a single saved life? Then we should feel bad about our choice, shouldn't we? Especially since some of the 500 will be visually impaired people.
Roundabouts are not the only way of slowing down traffic. There are other traffic-calming methods that can be used. Unfortunately, the experience with signalization as a traffic calmer is not encouraging. Even if the mean speeds are reduced, the top speeds are very high. And some of those top speeds are found just after the perpendicular walk signal indicates a clear crossing. And, what the roundabout has in its favor that most other traffic-calming measures don't have is that it allows for narrow streets, something very important for elderly pedestrians' safety.
Now, as my last words, if the suggested design criteria lead to no reduction in the rate of constructing roundabouts, and the proposed signals are such that pedestrians have the absolute right-of-way both when the signal is activated and deactivated (as is the formal rule today if they go blank) then the signalization should cause no bad safety-effects and we would all be winners. My concern is that the cost for such systems will be prohibitive, and the construction of roundabouts will be delayed.
Thank you for listening to my thoughts,
Per Gårder, Professor
Department of Civil Engineering
University of Maine
Lawrence T. Hagen, P.E., PTOE, October 22, 2002
As a general comment, too much of the guidelines are attempts to eliminate any engineering judgment in determining what is the appropriate traffic control treatment. This leads to "cookbook engineering" where everyone just blindly implements the cookbook approach. This one-size-fits-all approach is not good engineering, is not good public works, and is usually not serving the overall best interest of the public. Many of the recommended guidelines also seem to have been done with no consideration of the fiscal impact. However, with the ever-increasing demands and less money, operating agencies will have difficulty implementing the proposed guidelines
Alternate Circulation Path - (1102.3, 1111)
I would suggest that an exception for short-duration blockages of pedestrian paths should be included. If construction activities will block the path for a few hours or maybe one day, you could spend more time and disrupt more people by the installation and removal of the accessible and protected alternate path than by the actual construction activity. Short-term closure of a pedestrian path, where the pedestrian could utilize the other side of the road is a reasonable alternative.
Minimum Clear Width (1103.3)
48" width exclusive of curbs will be difficult to obtain in many areas with already-constrained right-of-way. I agree with some of the other posted comments that perhaps we should look to including the curbs.
Pedestrian Crossings (1105.2.1)
I do not support the widening of crosswalks in a sweeping blanket mandate. In many cases at large intersections, traffic engineers struggle to get the signal indications located within the 40 - 150' distance from the stop line as mandated by the MUTCD. Adding a couple of feet doesn't sound like much, but in many instances that could be the difference between four and eight signal structures (mast arms). I would prefer to see the 72 inch
Pedestrian Signal Phase Timing (1105.3)
I am adamantly opposed to mandating a walk speed of 3.0 feet
have crossed.
Pedestrian Crossing Length (1105.4.1)
This requirement would seem to mandate the removal of unsignalized crossings where the median width is less than 72 inches
Pedestrian Overpasses and Underpasses (1105.5)
I believe that requiring elevators where there is a elevation change over 60 inches
Roundabouts (1105.6)
I think mandating signalized pedestrian crossings at all roundabouts is one of the silliest ideas imaginable. Many roundabouts do not warrant signalization, so they would certainly not meet the warrants for the pedestrian crossings on the approaches. There certainly are some roundabouts with poor pedestrian performance, but many of those have design flaws in the roundabout. Many I have seen have the pedestrian crossing at the circulating roadway edge. By properly designing and constructing the pedestrian crossings at roundabouts, I believe that peds can be properly and safely accommodated without signals at most roundabouts. I think "YIELD TO PEDS" signs at the crosswalks should be tried first, and signalized ped crossings should only be a last resort if nothing else seems to work. However, either of these treatments should only be installed after an engineering study determines that they are the most appropriate traffic control device. I am also unsure what type of barrier is needed around roundabouts. Would a small strip of grass or other landscaping (like that shown in the picture) be an appropriate barrier? Guidance on the barrier is needed.
Turn Lanes at Intersections (1105.7)
Among other things, installation of the pedestrian activated signal at each segment of the crosswalk crossing slip lanes creates a maintenance problem. Large trucks routinely hit poles or devices that are out in the refuge island, so the maintaining agency has to repeatedly replace the equipment. Also, with the requirements of 1106.2.1, there is not room on most slip lane channelization islands to accommodate the spacing requirements. Similar to roundabouts above, I believe that if there is a problem, an engineer should study to determine the most appropriate traffic control and be able to choose the best answer for that intersection from the available solutions.
Accessible Pedestrian Signal Systems (1102.8, 1106)
My only comment here is related to the fiscal issue. In large metropolitan areas where there are large numbers of signals, the costs of retrofitting all of the signals with upgraded pedestrian features can be staggering, especially in this day and age when everyone's budget is being cut. Additionally, by replacing a simple pushbutton switch with a more sophisticated device that also vibrates and emits sounds, you will incur more maintenance expense. Please understand, I wholly support having accessible pedestrian devices where they are needed. However, given the additional capital and maintenance costs, is it good public works to install these devices where they may not be needed? Again, my objection is basically the one-size-fits-all approach.
Thank you for the opportunity to comment. Please let me know if you need additional information.
Larry Hagen
Lawrence T. Hagen, P.E., PTOE
Program Director - ITS, Traffic Operations, & Safety
Center for Urban Transportation Research (CUTR)
University of South Florida, College of Engineering
Bill Baranowski, P.E., August 9, 2002
I have read the proposed ADA rules for pedestrian crossings at roundabouts. I believe it is in the best interest of the public in the USA to
The 20 roundabouts that I have designed and that were built in the last 8 years in the USA have not experienced any pedestrian crashes. In special situations where a high number of pedestrians cross I would consider an manually or passively activated signal and I have successfully used raised crosswalks and activated flashing warning LED lights and additional illumination. It was used because of the perceived need and was not dictated to me by the ADA. I would prefer that the access board allow engineers to use the good judgement they are paid to use.
Will this mandate be applied to all regular traffic signal controlled intersections and any marked crosswalk at intersections or mid-block locations on our road system?
Roundabouts are accessible to all users, and the solution should not be dictated but considerations open to site conditions, engineering judgement, and further research. Such a ruling at this point in time is premature and may serve to inhibit the use of roundabouts which I believe have great potential to reduce injury crashes to pedestrians and thus save many lives in the USA. An example of crash reductions due to roundabouts is contained in a recent study of two roundabouts located in Howard, Wisconsin. The study may be accessed at the following link: http://www.co.brown.wi.us/Planning/transportation_division.html
This study shows the successful implementation of two roundabouts directly adjacent to an elementary school, a middle school and a new high school. The roundabouts achieved dramatic crash reductions and the school crossing guard indicated that the intersection is easier to cross since the roundabouts were installed. I would ask the board if it would be difficult to conduct similar trials if the proposed rule was enacted and enforced.
Bill Baranowski, P.E.
RoundaboutsUSA
August 15, 2002
Please add the following to your public input on the access board review of pedestrian safety at roundabouts. The attached designs for two 180' diameter roundabouts located in Riverdale, Utah are shown to illustrate the use of raised pedestrian tables at the entry and exits to roundabouts. The raised, textured and colored surface provides a tactile surface for pedestrian crossing. The gentle rise of the crossing area provides a decrease in speed to vehicles without reducing intersection capacity while creating a very visible crossing area that vehicles can see better than a painted crosswalk. It is possible that this design is superior to that of a pedestrian signal as well because flashing lights are often ignored by drivers.
See attached photos from grand opening parade held in July 2002.
Bill Baranowski
RoundaboutsUSA
Laura Oftedahl, October 27, 2002
I am a competent blind pedestrian - and strongly support accessible pedestrian signals. It is a very scary world crossing the street. I want to live, but need some help from this new technology. Thank you.
Laura Oftedahl