DETERMINANTS OF MOTOR VEHICLE FATALITIES AND FATALITY RATES IN ILLINOIS

In this study, four groups of factors were identified as those that influence fatalities in Illinois. These were divided into driver-related, vehicle-related, highway/environment, and demographics factors. Based on a descriptive analysis of fatality data, alcohol involvement, speeding, age, rural versus urban highways, divided versus undivided highways, snowy and icy days, location of crashes in relation to the intersection, and railroad crossing were identified as factors that affect fatalities. Correlation and regression analyses were conducted at the local level to identify regional differences in fatality data. Among factors related to the driver, crashes involving alcohol was perhaps the only factor that indicated a significant regional difference and some degree of correlation with higher fatalities. The correlation and regression analyses were also conducted at the State level to investigate the dependence of fatalities on the four factor groups from year to year. The results indicated that the proportion of drivers in the 16-19 year age involved in crashes contributes significantly to the fatality rate. Also, crashes involving drivers with any blood alcohol concentration level in their systems in general contribute significantly to traffic fatalities. The significance of weekday/weekend, night/day, urban/rural driving and snowy/rainy day conditions was also investigated through the correlation and regression analyses. The analyses revealed comparable results for weekday versus weekend driving. On vehicle-related factors, crashes involving passenger cars showed a strong correlation with the fatality rate. Finally, the results of a time series analysis indicated that motor vehicle fatalities are on the decline in Illinois.