Macrolevel Traffic Safety Longitudinal Comparison in Shanghai, China

To ensure improvements are made in the parts of the city currently most prone to crashes, this study conducted a 2009–2016 longitudinal comparison of the traffic safety in Shanghai at the level of the traffic analysis zone (TAZ). The police-reported crashes occurring in 2009 and 2016 within the downtown areas of Shanghai were examined to acquire a basic knowledge of the traffic safety development and spatial distribution characteristics of crashes. Considering that different zones within a city show significant heterogeneity in socioeconomic indicators, road characteristics, traffic patterns, and land-use features, a macrolevel traffic safety model was developed to capture the relations between the aggregate number of crashes and the various influencing factors. The study also identified hot zones for the two years to demonstrate the zonal changes in crash frequency. Results show that crash frequency had shifted significantly in suburban areas of Shanghai, with many hot zones having moved from the central areas of the city to suburban areas. Urban planners and decision makers can use this study to better understand the changes in crash distribution and contributing factors, permitting better targeted safety countermeasures.