Effects of Street Patterns an Injury Risks in Two-Vehicle Crashes

Road crashes not only claim lives and inflict injuries but also create an economic burden on society because of lost productivity. Many studies have identified factors affecting the frequency and severity of crashes. However, few, if any, studies have explored the effect of street pattern on injury risks in urban crashes. In this study, street pattern or urban form is classified into four categories: gridiron, warped parallel, loops and lollipops, and mixed patterns. Their effects on injury risk are examined together with other factors including road features, drivers' characteristics, crash characteristics, environmental conditions, and vehicle attributes. Calgary, Alberta, Canada, is chosen as the case study, and the logistic regression model is applied with reported crash data from 2003 to 2005 to investigate various factors. The results suggest that current popular patterns, including the loops and lollipops design, are safer than the conventional gridiron pattern from an injury risk perspective in the event of a crash.