Chia Wei Ensar Becic Christopher Edwards HumanFIRST Program Department of Engineering University of Minnesota

According to the National Highway Traffic Safety Administration: One pedestrian fatality event occurred every 2 hours Someone was injured by a vehicle every 9 minutes Among fatal events - 24% occurred at intersections Greater than 40 percent of all fatalities were from pedestrian collisions with transit buses

Left-turns had the highest proportion of pedestrian collisions Buses making left-turns are 4 times more likely to collide with pedestrians compared to drivers who proceed straight through an intersection

Mental workload increases during turning maneuvers at intersections Making a left turn at an intersection requires a greater number of subtasks Bus drivers complete a number of tasks that drivers of other vehicles do not

First Step Examine the cause of pedestrian and bus collision Metro Transit is creating a safety culture which promotes a zero collision policy Implemented a Look-and-See campaign to remind drivers to visually scan their surroundings prior to making a left-turn maneuver

Overall Goal Develop a clear picture of various subtasks that bus drivers complete during a left-turn maneuver Identify potential solutions for the left turn bus- pedestrian conflicts in order to reduce the frequency of collisions A pilot study examining the efficacy of the proposed solutions

Create a detailed analysis of various tasks that bus drivers complete when making a left turn Exogenous Endogenous A better understanding of these tasks will facilitate the development of concepts for support tools that help decrease left-turn bus– pedestrian collisions

Study Design: Interviews Three interviews were completed Each interview included two bus drivers or driver trainers Participants were asked to describe all tasks that they perform when making a left turn

As a tool during the interview, several large posters showing intersections were provided for drivers to explain their driving tasks

All of the subtasks and mental processes were classified into these categories Visual Broad visual inspection: observe big picture Focused visual search: search traffic lights and mirrors Working memory Monitoring a bicyclist Executive Determining the gap of an oncoming traffic Motor tasks Departing from a previous stop or turning at an intersection Unplanned events

Other Factors: Fatigue and stress at work Maintain strict schedules Deal with the passengers Operate the bus safely even in an inclement weather or bad traffic Visibility: Thunderstorms, blizzard or sun glare Road Conditions: Large snow banks during winter

Bus drivers engage in a large number of different subtasks during left-turns Solutions Aiding drivers in performing a particular subtask Completely removing a need to perform a particular subtask

Technologically Based Solution Aids in the performance of one task Track the movement of targets of interest and alert the driver if a target becomes an imminent danger

Infrastructure Based Solution Removing a need for performing a particular subtask A protective left-turn for buses reduce the perceptual and cognitive load.

Environmentally-Based Support Examine the impact of stress on bus drivers performance and frequency of collisions Poor stress coping = greater driving performance cost in challenging driving conditions

Pedestrian Solution Bus drivers represent only one side of the pedestrian/bus collision Warning alert for a pedestrian Alerting both parties of a collision may improve the odds of collision avoidance?

Pilot Simulator Study Objective Examine the potential efficacy of the proposed solutions

Pilot Simulator Study Technology Based Solution Pedestrian Detection System (PDS) Infrastructure Based Solution Left Turn Signal Environmentally Based Support Tool Two Driving Conditions

Two Driving Condition Groups Normal Driving Condition Driving in clear visibility condition Challenging Driving Condition Driving in foggy condition A noisy background Limited time in which to complete the drive

Driving Simulator

Total of 12 drives 4 drives included a potential collision scenario

Response to potential collision Accuracy of Response The time it took a driver to reduce their velocity by 25%

Accuracy of Response

Pedestrian Detection Systems Green Arrow – previously shown benefit, but potential hidden cost Coping with stressful driving conditions Alerting pedestrians Dumb noise Dynamic alert

Questions?