摘要：Understanding the dynamics of the daily number of fatal road traffic accidents is important for local authorities, police departments, healthcare facilities and insurance companies, enabling them to design preventive measures, provide appropriate emergency service and care and reliably estimate traffic accident insurance costs. In the present study, using the Fatality Analysis Reporting System provided by the U.S. National Highway Traffic Safety Administration, we construct a daily time series of the number of accidents for each state of the United States. We model the trend as well as yearly and weekly seasonality present in the time series and provide respective trend and seasonality statistics. Differences in accident rates and yearly seasonality between states were detected, clustering analysis being applied to identify clusters of states with similar yearly seasonality, weekly seasonal patterns for different states proving to be about the same.
