The impact of speed cameras on reducing the number of traffic accidents in the Czech Republic

The aim of this work was to investigate the long-term effect of speed cameras on accident rates in selected locations in the Czech Republic between the periods of 33 months before and 33 months after the installation of the radar and to evaluate the differences in the effectiveness of reducing the number of traffic accidents between locations with spot cameras and measured sections. Traffic accidents cause 1.3 million deaths per year, with speeding being one of the main causes. The data was obtained from the online database Nehody.cz, maintained by the Czech Police. The data includes accident counts 33 months before and after the installation of speed cameras and metered sections. Difference-in-difference (DID) and interrupted time series (ITS) analysis methods were used to analyze the data. The results showed that the ITS method is not suitable for less busy traffic flows due to the low number of accidents in which trend and seasonal components could not be observed, but it is applicable to busy roads outside municipalities. The DID method showed a decrease of 3.66 crashes per quarter on the busy road and 0.22 crashes in the village, but also increases of 0.5 and 0.4 crashes in other locations. ITS showed a statistically insignificant decrease of 3.89 crashes per quarter. Limitations of the work are the inappropriate method for municipalities, the limited number of locations, and not tracking other factors. The work can serve as a basis for further research and institutions responsible for traffic safety.