Abstract

Daylight saving time (DST), implemented as an energy saving policy, impacts many other aspects of life; one is road safety. Based on ten-year vehicle crash data in Minnesota, this paper evaluates long- and short-term effects of DST on daily vehicle crashes, as well as daily fatal crashes. Our statistical models not only include weather conditions and days of week as independent variables, but also consider traffic volume count on road. Our findings show that DST, in the long run, is associated with fewer daily crashes than standard time (ST). Yet, DST is found to be associated with higher odds of having more fatal crashes than ST. In addition, our data rejects the hypothesis that the first Sunday or Monday of time change in spring is associated with more fatigue-related crashes than Sundays before time change; nor do we find that the first Sunday or Monday of time change in fall is associated with more alcohol-related crashes than Sundays before time change. Of all weather conditions, snow is found to have the most significant effect on vehicle crashes; however, its impact on fatal crashes is nevertheless not statistically different from clear weather. Furthermore, Friday is associated with the most daily crashes, whereas Sunday and Saturday are associated with higher odds of more fatal crashes than weekdays.

Citations