During which month is it riskiest to drive in the United States?
OBJECTIVE
This study examined the variation in the U.S. road fatality rate per distance driven across the months of the year.


METHODS
The monthly fatality rates were analyzed for a 13-year period from 1994 through 2006.


RESULTS
The results indicate a systematic seasonal variation in the road fatality rate, with the highest rate in October and the lowest rate in March.


CONCLUSIONS
The obtained seasonal variation in the road fatality rate is likely a result of a joint influence of several factors that exhibit seasonal variations themselves (the duration of darkness, consumption of alcohol, proportion of older drivers, amount of leisure driving, and inclement weather).
Sivak
Michael
M
The University of Michigan Transportation Research Institute, Ann Arbor, Michigan 48109-2150, USA. sivak@umich.edu
D000063:Accidents, Traffic / Q000401:mortality* / Q000706:statistics & numerical data; D000704:Analysis of Variance; D001334:Automobile Driving; D016001:Confidence Intervals; D006801:Humans; D018570:Risk Assessment; D012621:Seasons; D014481:United States / Q000453:epidemiology