In the United States in the year 2009, there were over 114,000 fatalities and injuries among vulnerable road users (VRUs; pedestrians and pedal cyclists; NHTSA, 2010). 4092 pedestrians were killed in pedestrian-vehicle crashes. 630 pedal cyclists were killed in cyclist-vehicle crashes. Previous research has identified many factors that affect risk of injury and fatality for vulnerable road users. Inappropriate pedestrian behaviour, poor driver behaviour, and structural issues contribute to the risk to vulnerable road users. VRU risk at intermodal interchanges such as schools (Clifton & Kreamer-Fults, 2007) and bus stops may be due to factors such as the greatly increased number of pedestrians, the increased likelihood of poor pedestrian behaviour, and the lack of separation between pedestrians and vehicles (Zegeer & Bushell, 2012). While research has identified or proposed behavioural and engineering interventions to reduce risk, much of this research is based on macro-scale statistical models and not on actual analysis of human behaviour in response to the interventions. The objective of the research effort is to investigate the effectiveness of structural and in-vehicle interventions for modifying driver behaviour in order to increase the safety of vulnerable road users as drivers approach, pass through, and depart from intermodal interchanges. A 2x2x2x2 repeated measures mixed design was be used to evaluate the effect of facility structural elements (within-subjects: 8 designs; 2 (traffic signals) x 2 (marked crosswalks) x 2 (sidewalks)) and the effect of an in-vehicle VRU warning system (between-subjects: 2 levels). Members of the general public in and around Mississippi State University were be recruited to drive through simulated urban areas in a high-fidelity driving simulator. During the simulated drives, they drove through small urban areas that include an intermodal interchange facility (i.e. bus terminal). At these facilities, almost all users are pedestrians during at least one leg of their trip. During the pedestrian leg, the pedestrians are at risk as they may be required to move across and along roadways containing fast moving vehicles. As the driver passes a facility, the driver was expected to monitor and respond to the actions of simulated VRUs while focused on a primary search task. The structural elements associated with these interchanges varied (i.e. presence of traffic signals, presence of marked crosswalks, and presence of sidewalks). In addition to structural element variation, some drivers were equipped with an in-vehicle two-stage warning system that will provide a cautionary warning when approaching an area that may be high risk for VRUs and an imminent crash warning when an impending collision between a VRU and the vehicle is detected. This research provides a micro-scale understanding of how drivers respond to specific environmental changes that are designed to improve safety. We are particularly interested in the possibility that some interventions may actually increase risk to VRUs. For example, presence of marked crosswalks may create an expectation in the driver that all pedestrians will cross at the marked location and increase the risk of collision with a pedestrian that chooses to dart across mid-block. This research directly affects vulnerable road user safety by identifying the most effective interventions for improving driver behaviour near intermodal interchanges. The results affect structural environment design decisions and ultimately will save lives. (Author/publisher)
Abstract