What causes the most fatal car crashes in each US state

When passing an auto accident on the side of road, many people think to themselves, what happened?

The Auto Insurance Center, a car insurance news and information site, sought to answer that question. It compiled data on every fatal car accident in the US recorded by the National Highway Traffic Safety Administration's (NHTSA) Fatal Accident Reporting System from 2009 to 2013.

The data includes driver, passenger, and pedestrian fatalities.

The findings, shown below in map form, show what causes the most fatalities in every US state.

In a majority of states, the mistake of failing to stay in your lane kills the most people. The second-most common behavior was failing to yield the right of way, the leading cause in seven states.

To find out which states lead the country in each of these fatal driving behaviors, the Auto Insurance Center took the total number of crashes associated with each of these behaviors by state and divided that number by each state's population to arrive at a per-capita metric for accurate comparison.

The Auto Insurance Institute found all the states particularly high rates of fatalities for a specific behavior included large rural areas where thinly distributed law enforcement can't adequately enforce safe driving laws.

Drunk Driving

The Auto Insurance Institute also concluded that deaths from drunk driving are more prevalent in rural areas that lack public transportation. A potential drunk driver in North Dakota or Montana might not have the luxury of calling a cab or taking the subway compared to somebody in Washington D.C. or New York.

The exception to this rule is Utah, where strict liquor laws and a large Mormon population result in fewer drunk drivers.

Speeding

Once again, rural areas prove more deadly for motorists when speeding. The Auto Insurance Center notes that in places like Montana and Wyoming, rural roads can stretch on for miles with little traffic to slow drivers down whereas urban areas often feature congested roadways.

Bad Weather

The following three maps compare two weather conditions to reveal which causes more deaths in each state.

To start, rain-slicked roads tend to kill more drivers than snow in most states, but in the Midwest, snow tends to be more deadly.

Driving in the fog claims more lives than driving in the snow in the South and along the coasts, but the opposite is true in the northeast and midwest.

Finally, sleet is more deadly than crosswinds (wind blowing perpendicular to your direction of travel) in most of the country, but in the southwest, it's the opposite.