The number of fatal injuries resulting from motor vehicle accidents has dropped significantly over the last 10 years. In 2003, 42,884 were killed in motor vehicle accidents. By 2013, that number dropped to 32,719. While the death rate across the country for 2013 was roughly one out of every 10,000 U.S. residents, the fatality rate varied considerably state by state.

Only Texas had more than 3,000 fatal road accidents. However, after adjusting for population, many states had a significantly higher rate of fatal accidents than Texas. To rank the most dangerous states to drive in, 24/7 Wall St. reviewed state by state fatality data from the Insurance Institute of Highway Safety (IIHS) along with rural and urban travel data provided by the Federal Highway Administration (FHA). With 22.6 roadway fatalities for every 100,000 residents, Montana is the most dangerous state in the country to drive. By contrast, the corresponding rate in Massachusetts is 4.9 fatalities for every 100,000 residents, making it the safest state in the country to drive.

Click here to see the most dangerous states to drive in.

Many of the most dangerous states to drive in share several characteristics. In an interview with 24/7 Wall St., Russ Rader, a spokesman for the IIHS, explained that the most significant factor that differentiates the safest states from the most dangerous ones is how urban or rural it is. According to Rader, nearly across the board, “rural states have higher fatality rates than urban ones.”

In fact, in four out of the five most most dangerous states, well over half of all miles driven in 2013 were in rural areas. By contrast, in 22 of the 25 safest states, less than half of all miles driven were through rural areas. Rader explained that this makes a difference because on rural roads, “speeds are higher and there are more two lane roads (where) risk is greater for head-on collisions.” By contrast, in urban areas, “speeds are lower, there’s more congestion, and that means that fatal crashes are less likely.”

The choices an individual makes as a driver or passenger of a vehicle also matter a great deal. One of the most obvious ways to reduce the likelihood of a fatality in the event of an accident is to buckle up. Seatbelt use tends to be lower in states with the highest rate of roadway fatalities, and the opposite is true in states with the lowest rates of death on the road. Nationwide, about 87% of people use a seatbelt when riding in a passenger vehicle. In 10 of the 15 safest states to drive in, seatbelt use is greater than or equal to the national rate. Conversely, seatbelt use is below the national rate in 12 of the 15 most dangerous states, including Idaho, where only 62% of residents buckle up, the lowest rate of any state in the country.

To rank the safest and most dangerous states to drive in, 24/7 Wall St. reviewed state by state fatality data from the IIHS along with urban and rural travel data provided by the FHA, each for 2013. The number of fatal roadway deaths was then adjusted for population, noted as fatalities per 100,000 residents. Penalties for alcohol impaired driving by state were provided by WalletHub. Fatal injuries due to vehicle accidents include pedestrian and cyclist fatalities.

These are the most dangerous states to drive in.

Correction:  A previous version of this article incorrectly represented a data set — drivers killed with known BAC (blood alcohol content) — as the proportion of drivers killed in a car crash that had alcohol in their blood. In fact, the data set — which came from IIHS —  only refers to the share of drivers killed that were tested for a BAC, and makes no claim about whether these drivers had alcohol in their system.