Road traffic accidents are believed to be associated with not only road geometric feature and traffic characteristic, but also weather\ncondition. To address these safety issues, it is of paramount importance to understand how these factors affect the occurrences of\nthe crashes. Existing studies have suggested that the mechanisms of single-vehicle (SV) accidents and multivehicle (MV) accidents\ncan be very different. Few studies were conducted to examine the difference of SV and MV accident probability by addressing\nunobserved heterogeneity at the same time. To investigate the different contributing factors on SV and MV, a mixed logit model\nis employed using disaggregated data with the response variable categorized as no accidents, SV accidents, andMV accidents. The\nresults indicate that, in addition to speed gap, length of segment, and wet road surfaces which are significant for both SV and\nMV accidents, most of other variables are significant only for MV accidents. Traffic, road, and surface characteristics are main\ninfluence factors of SV and MV accident possibility. Hourly traffic volume, inside shoulder width, and wet road surface are found\nto produce statistically significant random parameters. Their effects on the possibility of SV andMV accident vary across different\nroad segments.
Loading....