This book examines driver, vehicle, roadway and environmental characteristics associated with increased crash involvement by older drivers. Project activities were designed to prioritise the situations causing problems for older drivers based on the magnitude of the crash problem, older driver's degree of over-representation, the likelihood of serious injury, or other criteria of interest. The resulting list of the most problematic situations frame further discussions of how age-related functional decline can mediate increased crash risk for older drivers, and hopefully, point to potential countermeasures for lowering this risk.