The reported two tasks (Task 1.1, Task 1.2) explored comprehension of a new signal: The flashing pedestrian indicator (FPI). This signal, which alternates between a yellow arrow and a symbol of a pedestrian, is intended to help alert drivers to the potential presence of pedestrians, to encourage drivers to scan for pedestrians, and to promote caution and yielding behaviours related to pedestrians within a crosswalk while a driver is making a turn at a signalised intersection. The ultimate goal of this research is to prevent pedestrian crashes, a goal that is especially relevant to the state of Florida given its above-average pedestrian fatality rate and its large and growing older adult population. Older adults are at greater risk as pedestrians compared to their younger counterparts for a number of reasons (decreased ability to sustain crash forces, slower walking speeds which increase exposure risk). Tasks support and inform the Florida Department of Transportation’s (FDOT) Aging Road User Strategic Safety Plan. Task 1.1 presented younger (21-35), middle-aged (50-64), and older (65+) drivers with driving scenes depicting various signal states, including the FPI, and participants were asked the meaning of these signals. In both open-ended and multiple choice formats, we found that participants easily understood the meaning of the FPI. The large majority of participants understood it to indicate the potential presence of a pedestrian. Most participants indicated that in response to the FPI, drivers should be cautious, scan for, or yield to pedestrians while making a turn. Task 1.2 presented participants with scenes of an intersection, with a pedestrian either present or absent in the crosswalk immediately to the right. Participants were asked to imagine they were a driver turning right and to indicate what the correct action would be for various signal states (go, stop, yield). Critically, we manipulated whether the intersection contained or did not contain an FPI. Yielding decisions were increased significantly when the FPI was depicted compared to an equivalent situation in which a circular green signal was presented. This was true whether or not a visible pedestrian was present. The FPI also slowed responses when a pedestrian was absent, likely indicative of greater search for pedestrians. Some participants were confused regarding the meaning of the FPI for drivers going straight through the intersection (participants often thought that drivers going straight would also need to be cautious of pedestrians). Our scenario featured a right-lane that served both as a through lane and as a lane that would allow a right-turn. This meant that the FPI and circular green were presented simultaneously in the same signal above this lane. The observed confusion may be diminished for intersections with a dedicated right-turn lane and additional research should explore this possibility. Further, participants often made a “yield” decision in response to the FPI even when no pedestrian was present. Observed confusion may impact traffic flow. The source of this confusion and potential solutions need to be addressed before implementation of the FPI can be recommended. Based on these findings, we offer a number of recommendations: The FPI is a promising signal in that many drivers demonstrated comprehension. However, the reported studies raise important questions that need to be answered before final recommendations can be made regarding FPI implementation. We recommend additional studies that address confusion. In particular, whether confusion is unique to scenarios in which the FPI is located above a lane that allows both through traffic and a right turn. Confusion may be less for intersections that feature the FPI above a dedicated right-turn lane. We recommend studies of how roadway geometry impacts comprehension for drivers going straight through the intersection and drivers turning right. Supplemental signs and driver education (e.g., FPI tip cards) are other solutions that might be investigated to address confusion. The reported studies are a first step in which driver comprehension and basic decision processes were tapped. Another necessary step is to evaluate driver behaviour. This can be accomplished through a driving simulator study similar to other simulator studies that have examined driver/pedestrian interactions (e.g., Boot et al., 2014). Outcome measures can include whether the driver appropriately yields to crossing pedestrians when turning right and whether drivers respond inappropriately to the FPI (e.g., slowing or yielding) when driving straight through the intersection. Finally, the response of the pedestrian is another important issue to consider. This is especially important as the FPI begins to mix together signals typically directed at drivers (yellow arrow) and signals typically directed at pedestrians (walk sign). Studies are needed to further explore pedestrian response to the FPI. (Author/publisher)
Samenvatting