Aging road user studies of intersection safety.

Task 1.1 assessed younger (21-35 years), middle-aged (50-64 years), and older (65+) drivers’ ability to quickly perceive the presence of marked/unmarked crosswalks and pedestrians within them in computer-based laboratory tasks that recorded response times and eye movements. There was an advantage for special emphasis markings in that they were detected more quickly and accurately compared to standard markings. However, there was no evidence that markings improved or reduced pedestrian conspicuity. In Task 1.2, pedestrians were observed at two signalized intersections (Monroe and Georgia, Monroe and Carolina) in Tallahassee to observe the effect of different crosswalk markings on pedestrian behavior. Special emphasis markings did not induce more pedestrians to cross at signalized crosswalk locations compared to crossing midblock at an unmarked location. A simulator experiment (Task 1.3) found that different crosswalk markings had no impact on driver behavior. Task 2.1 and Task 2.2 examined younger and older adults’ perception-reaction times to yellow traffic signals in a driving situation. In Task 2.1, modeling was used to estimate this value for younger and older adults, while Task 2.2 provided this value through a driving simulator task. Both revealed that older adults needed substantially more time to react to a yellow signal compared to younger adults (Modeling: 767ms, Simulator Study: 803ms). Task 3.1 reviewed the Flashing Yellow Arrow (FYA) literature and suggested a need for further study, especially with older adults, and with respect to the effectiveness of FYA educational materials. A lab study (Task 3.2) found that participants of all ages infrequently misunderstood the meaning of a FYA signal in a way that would result in a crash. However, a simulator study (Task 3.3) found that behavioral measure of comprehension were higher for participants exposed to FDOT’s FYA tip card. Recommendations for the implementation of each of these countermeasures are discussed.