A multifaceted relationship between congestion and accidents on highways: evidence from D-100 highway in Istanbul

Official URL: http://risc01.sabanciuniv.edu/record=b1606874 (Table of Contents)

Using a comprehensive traffic flow data for D-100 Highway in Istanbul, this thesis empirically analyzes the effects of congestion on highway accident frequency. Prior studies looked at this relationship in the context of injury and fatal accidents and found accident likelihood to be decreasing with congestion. We concentrate on property damage accidents and found that their likelihood increases with congestion. Moreover, in our data, the relationship is nonlinear: congestion increases accident likelihood under hypercongested traffic conditions but it has no significant effect under (normally) congested traffic conditions.