The map below shows the number of fatal accidents in each state. By looking at the map you can see that clearly California, Texas, and Florida have the most accidents. These states also have the highest population across the US (excluding New York because not many people drive in NY city).
To normalize for this, we bring in state population data and divide the number of fatal accidents in 2015 by the number of people living in each state in 2015. This will give us the accident fatality rate. The map below reflects the accident fatality rate in each state.
Now we can clearly see that Wyoming, Montana, Mississippi, and South Carolina have the highest accident fatality rate in the US.