Surrogate Safety Assessment Model (SSAM): [techbrief]

2009PDFTech ReportFHWA-HRT-10-020HRDS-05/10-09(Web)EHighway safetyTraffic safetyIntersectionsTraffic simulationUnited StatesUnited States. Federal Highway Administration. Office of Research, Development, and TechnologyGettman, DouglasShelby, StevenUnited States. Federal Highway Administration. Office of Research, Development, and TechnologyTurner-Fairbank Highway Research CenterChen, C.Federal Highway AdministrationThe safety of intersections, interchanges, and other traffic facilities is most often assessed by tracking and analyzing police-reported motor vehicle crashes over time. Given the infrequent and random nature of crashes, this process is slow to reveal the need for remediation of either the roadway design or the flow-control strategy. This process is also not applicable to assess the safety of roadway designs that have yet to be built or flow-control strategies that have yet to be applied in the field.This TechBrief summarizes the research and development of the Surrogate Safety Assessment Model (SSAM), a technique combining microsimulation and automated conflict analysis, which analyzes the frequency and character of narrowly averted vehicle-to-vehicle collisions in traffic, to assess the safety of traffic facilities without waiting for a statistically above-normal number of crashes and injuries to actually occur