, Fmr Director, HumanFIRST, Mechanical Engineering
Pedestrian fatalities that result from left-turning buses at intersections occur nationwide, with bus drivers often held accountable for such collisions. The factors that contribute to these collisions are unclear. Left turns at intersections are difficult for drivers of all types of vehicles. It is likely that the complexity of completing the left-turn maneuver is a contributing factor. There are many "competing" tasks for drivers' attention at intersections, such as monitoring oncoming traffic. Bus drivers likely complete additional tasks that drivers of other vehicles do not. This project included two specific research efforts. The primary objective of the first was to conduct a task analysis of a left-turn maneuver by a bus driver to provide insight into the cognitive and perceptual processes that bus drivers complete while performing this maneuver. An additional goal of the first research effort was to develop potential countermeasures to help reduce the frequency of bus-pedestrian collisions. The interviews conducted as part of the task analysis revealed that drivers engage in many subtasks and cognitive/perceptual processes when completing a left-turn maneuver. The researchers proposed two potential interventions for the reduction of bus/pedestrian collisions--one to aid a driver in detecting pedestrians at a crosswalk, and a second to remove the need to perform a particular attention-demanding subtask in order to reduce the cognitive and perceptual load that drivers experience during this maneuver. The second research effort was designed as a pilot simulator study in which the researchers examined the potential effectiveness of proposed interventions. This second study uncovered unanticipated findings (e.g., a high rate of collisions with pedestrians) that may be due to the nature of the simulator studies--specifically, lack of real-world consequences. The results of the pilot study provided sufficient data for further examination of different support tools for reducing fatalities between left-turning buses and uncovered a potential relationship between work-related stress and driving performance.