What is the current 'state of the art' regarding the design of safe crosswalks, especially in urban settings?
Treatments to improve the safety of crosswalks include:
- Raised mid-point median.
- Pedestrian-initiated amber, overhead flashing lights.
- Stopline painted on the roadway some distance in advance of the crosswalk (30 > feet)
- Increasing the illumination of the crosswalk as well as having its illumination arise from the side (rather than from above the crosswalk).
- Flashing warning lights mounted beside the road at a lower level than the ones currently placed directly over the crosswalk.
When dealing with countermeasures to reduce pedestrian crashes (or other types of crashes), it is important to first gain a thorough understanding of the site in question, including the characteristics of past crashes, vehicle speeds, volumes, pedestrian behavior and characteristics, number of lanes, sight distance, type of traffic control, etc. and to conduct a site inspection. This is comparable to thoroughly examining a patient who complains of pain or another medical condition. Until the cause of the ailment is well-understood, it is difficult to prescribe the most effective treatment.
Pedestrian fatalities may be the result of a combination of unsafe behaviors by the driver and/or pedestrian which may or may not be related to a treatable site deficiency or condition. Did the driver fail to see the pedestrian in the crosswalk? Was the vehicle speeding? Did the pedestrian not look for on-coming traffic before stepping into the street? Was there limited sight distance between the driver and pedestrian?
One of the classic types of events that occurs in marked crosswalks on multi-lane roads is the "multiple threat" crash, which involves a vehicle in the curb lane that stops for the pedestrian right in front of the crosswalk. The pedestrian's view of the oncoming vehicle (in the adjacent lane) is blocked by the stopped vehicle, and the pedestrian fails to look into the second lane and is struck by the oncoming vehicle (whose driver cannot see the pedestrian until it is too late to stop). This type of multiple threat crash can, in some cases, be prevented by the advance stop bar (or yield line), which may be placed 30 to 50 feet in advance of the marked crosswalk, peferably with a "Stop Here for Pedestrians" or "Yield Here for Pedestrians" sign, depending on the law in effect. Of course that does not guarantee that every stopping vehicle will stop at the stop line (or yield line), so preventing such a pedestrian crash is not guaranteed.
Having a raised median island is shown to reduce pedestrian crashes by about 40 percent. Additionally, a well-lighted crossing can benefit pedestrians in dark or dusk conditions. The effectiveness of a flashing yellow or red lights is unclear. At an uncontrolled (unsignalized) location, a flashing yellow light may not convey a clear message to drivers on what they are supposed to do. Likewise, results are mixed from the use of the "flashing in-pavement lights." Even though these devices are now allowed in the U.S. MUTCD (Manual on Uniform Traffic Control Devices), it is not clear that they are an effective solution for pedestrian crossing problems, particularly on multi-lane roads (and also in the daytime when they are virtually undetectable by drivers).
A traffic signal may be warranted in some locations. The City of Tucson recently found a very high level of motorist compliance (yielding to pedestrians in crosswalk) with a HAWK traffic signal. Is has a standard traffic signal, with supplemental signing ("Pedestrian Crossing" and "Stop for Pedestrians") and also a push-button device which immediately activates the signal. The City of Tucson has now installed these devices at about 30 locations citywide and found that about 95 percent of motorists comply.
Additional Resources:
- PEDSAFE contains details on 48 different types of pedestrian treatments, "expert system" software to help in the diagnosis of problems and candidate countermeasures, and 71 case studies (success stories) of pedestrian treatments.
- "How to Develop a Pedestrian Safety Action Plan" provides information on enhancing pedestrian safety programs and activities, including identifying safety problems, analyzing information, and selecting optimal solutions.
- Crosswalks
