Turner-Fairbank Highway Research Center

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Traffic Operations Control for Older Drivers. Final Report

Product Type

Research Report


R. Knoblauch, M. Nitzburg, D. Reinfurt, F. Council, C. Zegeer, and C. Popkin




The objectives of this project were to define the problems older drivers and pedestrians have at intersections, and make recommendations for changes. A literature review, a detailed accident analysis, and eight focus groups were conducted to identify the specific kinds of traffic-control-related problems experienced by older drivers and pedestrians at intersections. Three problem areas were targeted. The Left-Turn Signal Comprehension Study examined the lack of understanding associated with a variety of protected and permitted left-turn signal displays. It was found that many drivers, young and old alike, do not understand the protected/permitted signal phasing. Efforts to improve motorist comprehension of left-turn signal phasing should be targeted at the entire driving population. Older pedestrians frequently indicated that they don't have enough time to cross the street. This complaint is exaggerated by the lack of understanding of the clearance--Flashing DON'T WALK--phase. The Pedestrian Signal Comprehension Study involved the development and evaluation of a pedestrian signal explanation placard. The wording of the placard was empirically developed. Field testing failed to demonstrate a change in pedestrian comprehension or compliance. However, the placard did produce a small, but significant, increase in pedestrian comprehension level. Recommendations for the wording of the pedestrian signal education placard are made. The Driver Signal Response and Stopping Behavior Study compared the responses of older and younger drivers to amber onset and the braking ability of older and younger drivers. Testing was done in a controlled field test facility with the subjects driving their own cars. No important differences between older and younger drivers were found. Current standards for amber signal duration and red signal onset do not need to be modified.

Link To Research Report

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Older drivers
Older pedestrians
Left-turn signals
Pedestrian signals

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