Trends in Motor Vehicle Traffic Fatalities in the United States, 1968-2010

Background: Studies that typically estimate epidemiologic trends as long-term change between two time periods ignore short-term changes in trends occurring during the study period. This study describes long- and short-term trends in motor vehicle (MV) traffic fatalities between 1968 and 2010 using a method typically employed in cancer epidemiologic trend analyses.  

Methods: Long-term and short-term (linear piecewise segments) trends in age-specific MV fatalities were compared for males and females using the Joinpoint Regression Program. Data for the study were from the Compressed Mortality Files of death certificates filed in all 50 states and DC.

Results: All age-sex groups, except women 25-34 and 35-44 years, experienced significant long-term declines in MV fatalities between 1968 and 2010. Distinct short-term trends were observed during this time period. After a period of initial decline until the mid-1970s in both males and females, short-term trends in fatalities differed for women and men. For women under 65 years, fatalities declined steadily until the early to mid-2000s, whereas for men, fatalities declined sharply until the mid-1990s and then leveled off until the mid- 2000s. Children (<1-14 years) of both sexes had similar short-term trends, but men and women 65+ years experienced different trends from the 1980s-2000s. All age-sex groups experienced sharp declines from the mid-2000s to 2010.

Conclusions: While most age-sex groups experienced significant long-term declines in MV fatalities in the study period, the Joinpoint regression method allowed for the identification of distinct patterns of short term trends that evidently differed between males and females.