Out-of-state drivers involved in high rate of crashes out West

May 26, 2011
  • umichnews@umich.edu

ANN ARBOR—With the summer tourist season upon us, out-of-state drivers may want to be extra careful if they’re planning to vacation in the American West, say University of Michigan researchers.

A new study by the U-M Transportation Research Institute appearing in the June issue of Traffic Injury Prevention shows that a larger percentage of drivers involved in fatal crashes in several Rocky Mountain and Great Plains states are from out of state compared to other areas of the United States.

UMTRI researchers Michael Sivak and Brandon Schoettle examined data from the Fatality Analysis Reporting System for about 50,000 fatal crashes nationwide in 2008.

They found a wide variation across the 50 states in the percentage of drivers involved in fatal crashes who are from out of state. While the West Coast states are near the bottom of the range (only 5 percent in California—the lowest rate overall—and 9 percent in Washington), most of the rest of the western states are near the top.

Wyoming has far and away the highest proportion of drivers involved in fatal crashes who are from out of state—41 percent. South Dakota (27 percent) and New Mexico (24 percent) rank second and third, respectively. Montana (23 percent), Nevada (21 percent), Idaho (20 percent), Nebraska (17 percent) and Kansas (16 percent) also rank among the top dozen or so states with the highest percentage of fatal crashes involving drivers from other states.

According to Sivak and Schoettle, several coastal states have lower rates of fatal crashes involving out-of-state motorists (California, Washington, Florida, Maine) partially because they are not fully surrounded by other states. However, several New England states rank in the top 15, including Vermont (23 percent), Rhode Island (18 percent), New Hampshire (18 percent) and Connecticut (15 percent). Other eastern states, such as Delaware, Maryland and Virginia rank in the top 20, and West Virginia is fourth overall with 24 percent of fatal crashes involving out-of-state drivers.

The Midwest has four of the bottom 10 states for fatal crashes involving motorists from other states: Michigan (5 percent), Ohio (8 percent), Minnesota (9 percent) and Illinois (9 percent).

The UMTRI researchers also used 2008 data from the National Highway Traffic Administration to correlate the percentages of drivers involved in fatal crashes who were from out of state with the states’ fatality rates per distance driven and found a positive correlation.

“This finding is consistent with the hypothesis that states with higher fatality rates tend to have a higher percentage of out-of-state drivers among the persons involved in fatal crashes,” Sivak said. “However, whether this relationship is causative cannot be ascertained from the available data because we do not have the information about the relative distance driven in each state by out-of-state drivers.

“Future research should attempt to delineate the types of fatal crashes that have over-involvement of out-of-state drivers. Research along these lines would not only provide better understanding of crashes on unfamiliar roads, but also likely yield avenues through which to address these types of crashes.”


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