Effects of fixed speed cameras on spatio-temporal pattern of traffic crashes: Ankara case

Abstract

Considering that speeding is the predominant factor in severe crashes, this study aims to investigate the effectiveness of fixed speed camera enforcement on spatio-temporal pattern of traffic crashes in Ankara, Turkey. We investigated 1448 crashes involving fatality and/or injury on the sections with and without fixed speed camera in Ankara for the years of 2009 and 2011. Network-based Kernel Density Estimation Method was used to examine the spatial distribution of crash density pattern for pre and post camera instillation years. Comparison of crash statistics between 2009 and 2011 revealed that the fixed speed cameras installed in 2010 resulted in 23% decrease in the number of crashes involving fatalities and/or injuries, 50% in fatalities, and 27% injuries in the examined regions. Moreover, the fixed speed cameras were found to be significantly effective in their catchment area bands in 7 out of 18 indicators including total crashes, injuries, single vehicle crashes, weekdays crashes, noon crashes, evening crashes, and summer crashes. Consistent with the previous studies, findings showed that the fixed speed cameras were effective, especially in reducing traffic injuries and crashes with fatalities or injuries.