Summer, with its heat, alcohol supply and laid back attitudes, is not the most dangerous driving season. Neither is winter, despite unpredictable weather and countless holiday parties.

According to a new study by the University of Michigan, fatality crash rates are highest in the Fall. The US sees 10 point 2 deaths on the road per billion kilometers.

Michael Sivak of the University’s Transportation Research Institute found that October, November and December have the highest fatality rates. March has the lowest, with 8 point 8 deaths per billion kilometers. February and April are also quite low, he found.

Sivak said that the risk of a fatality per distance driven in October is about 16 percent greater than the risk in March.