Toward a Better Understanding of Vulnerable Road User Safety Issues

Project Description Phase 1 of this research investigated the precursors of motor vehicle crashes and near crashes experienced by SHRP2 drivers involving bicyclists and pedestrians. We examined variables in the Trip and Event datasets as well as information in the SHRP2 database describing driver demographics, functional status, risk perception, and knowledge to determine which variables may account for significant variance in the likelihood of occurrence of these crash types. We also reviewed front camera video – in which only the roadway is visible, not the driver’s face – of each crash event. Phase 2 expanded and refined the methodology used in the Phase 1 exploratory analyses to examine the relationship between older drivers’ performance in freeway merging situations where ramps and acceleration lanes are characterized by more favorable (less demanding) versus less favorable (more demanding) highway design elements. We examined performance measures (kinematic data) for age-matched drivers with varying functional profiles who have each traversed a common set of ramps/acceleration lanes, and/or intersections, under known operating conditions, using a larger sample drawn from multiple SHRP2 sites. Planned analysis methods included between-groups comparisons (ANOVA) and regression modeling (using functional status to predict differences in kinematic measures). Data Request Scope For Phase 1.1, approximately 100 Events were identified according to criteria in Appendix A. Time series, speed limit, event, trip, and driver data and front video were extracted for each of these events. For Phase 1.2, additional driver information was requested for all drivers age 60 or over. For Phase 2, maneuvers of interest were identified at 27 intersections. Trip, driver, and time series data and front video were extracted separately for 1) the time period 15 seconds before entry to the Reference Link ID and 2) the time period 15 seconds after exit of the Reference Link ID. See Appendix A for more details. Data Specification See Appendix A. --