Exploring the spatiotemporal correlation among traffic crashes on arterials with signal coordination

Abstract

oordinated signalization has been applied on arterials since 1960s. However, long-term effects of signal coordination on traffic safety have not been fully discussed, especially in terms of the temporal and spatial variations among crashes. With Bayesian Poisson lognormal model, the paper compares three types of spatiotemporal correlations on the coordinated arterials, including the fixed spatial and linear temporal variation, the fixed spatial and linear-quadratic temporal variation, and the time-varying spatial interaction. With 9-year crash data from Michigan, the study demonstrates that (1) different models should be separately applied for the coordinated arterials, e.g. BPLM with the time-varying spatial interaction fits roadway segments, and BPLM with the fixed spatial and linear temporal variation excels at signalized intersections and (2) the temporal and spatial variations are correlated on roadway segments. The findings emphasize the importance of conducting the safety analysis regularly and dynamically monitoring driving behaviors along the roadway segments.