Study of Accidents at Signalized Intersections -- Phase I Final Report

745717https://doi.org/10.21949/15182771997Phase I - FinalPDFTech ReportFHWA/MT-96/81298129AgeCrash dataCrash diagramsCrash ratesCrash reportsCrash severityCrash typesCrashesDriversSignalized intersectionsStatisticsTrend (Statistics)MontanaMontana. Department of Transportation. Research, Development and Technology Transfer ProgramWolverton, Jereen J.Mounce, John M.Montana State University (Bozeman, Mont.). Department of Civil EngineeringMontana. Department of Transportation. Research, Development and Technology Transfer ProgramUnited States. Federal Highway AdministrationUS Transportation CollectionThe objective of this project is to examine accident data at signalized intersections for accident patterns and trends that are susceptible to correction in Montana. The Scope of Work consisted of conducting a literature review, assimilating accident trend statistics, establishing variables of influence and determining significant causal patterns. Accident trend statistics were assimilated for the 3 year period from 1992 to 1994. The following variables were evaluated: type of accident, severity, alcohol involvement, roadway surface conditions, age of drivers, and contributing factors. Montana percentages for these variables were compared to other studies and were found to be similar. Accident trends between Montana's six largest cities (Billings, Great Falls, Missoula, Butte, Helena and Bozeman) were also investigated. Accident type percentages were similar for these cities. Accident rates were calculated along the State Primary Routes in Montana to establish variables of influence and significant causal patterns. Twenty-five intersections were selected for further study, in which accident report files were obtained and collision diagrams were constructed. From these collision diagrams, relationships were investigated to determine trends for Montana's signalized intersections. Variables that were determined to affect accidents in Montana were traffic volume and population of the city in which the accidents occurred. Angle and rear-end type accidents accounted for the largest percentages of accident types. When compared to other states and studies, Montana's accident characteristics are similar.90