Exploring the Effect of Motor Traffic on Street Crime

Traffic impacts road safety in a variety of ways that are often overlooked. Beyond its environmental impacts and the obvious risks to pedestrians, we hypothesize that heavy motor vehicle traffic can also increase crime in public spaces. We develop this hypothesis based on a broad range of established theories of crime and test it using longitudinal data from Understanding Crime and two-way fixed-effects models. We find that the perception of crime is higher in neighborhoods with high levels of motor vehicle traffic. More importantly, the two phenomena are correlated over time, suggesting a likely causal effect. Finally, we point out that the causal effect of motor vehicle traffic on crime in public spaces is likely mediated by collective effectiveness. That is, traffic weakens community bonds, thereby reducing the effectiveness of informal surveillance.