title: Exploring spatial autocorrelation of traffic crashes based on severity.
abstract: As a developing country, Iran has one of the highest crash-related deaths, with a typical rate of 15.6 cases in every 100 thousand people. This paper is aimed to find the potential temporal and spatial patterns of road crashes aggregated at traffic analysis zonal (TAZ) level in urban environments. Localization pattern and hotspot distribution were examined using geo-information approach to find out the impact of spatial/temporal dimensions on the emergence of such patterns. The spatial clustering of crashes and hotspots were assessed using spatial autocorrelation methods such as the Moran's I and Getis-Ord Gi* index. Comap was used for comparing clusters in three attributes: the time of occurrence, severity, and location. The analysis of the annually crash frequencies aggregated in 156 TAZ in Shiraz; from 2010 to 2014, Iran showed that both Moran's I method and Getis-Ord Gi* statistics produced significant clustering of crash patterns. While crashes emerged a clustered pattern, comparison of the spatio-temporal separations showed an accidental spread in distinct categories. The local governmental agencies can use the outcomes to adopt more effective strategies for traffic safety planning and management.
authors.affiliation: Department of Urban Planning, Traffic and Transportation Research Centre (TTRC), Shiraz University, Iran. Electronic address: soltani@shirazu.ac.ir.
authors.forename: Ali
authors.initials: A
authors.lastname: Soltani
authors.affiliation: Department of Urban Planning, Traffic and Transportation Research Centre (TTRC), Shiraz University, Iran. Electronic address: s.askari@shirazu.ac.ir.
authors.forename: Sajad
authors.initials: S
authors.lastname: Askari
mesh_terms: D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D016000:Cluster Analysis; D005843:Geography; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008962:Models, Theoretical; D012307:Risk Factors; D062206:Spatial Analysis; D018709:Statistics, Nonparametric; D015599:Trauma Severity Indices; D014505:Urban Population
keywords: Severity; Spatial statistics; Spatiotemporal clustering; Vehicle-related crash