Safer Streets: The Measured Effectiveness of Hartford’s CitywideTraffic Calming Program

摘要

The City of Hartford, Connecticut made an innovative move in 2005 when itrndeveloped a comprehensive citywide traffic calming master plan – the first of its kind in thernUnited States. This plan, and the process used to develop it, was presented at the 2005 ITErnTechnical Conference and Exhibit. Two years later, as this ambitious plan is graduallyrnimplemented, the city is collecting “before” and “after” data for many of the traffic calmingrndevices so that their impact on vehicular safety can be measured and so that future deploymentsrnmay be validated. This paper presents a case study on the effects of deploying road diets on crashrnfrequency. Roads that were placed on road diets were compared to similar roads that did notrnreceive any treatments. The Empirical Bayesian (EB) method was used to predict the “expected”rncrash rate during the “after” period without implementation based on the control sites. Thernobserved “before” crash rates, the crash rate expected without improvement, and the observedrn“after” crash rate were compared and discussed.