Michigan became the first Midwest state and the tenth in the nation to legalize marijuana for recreational use during Nov. 6 voting. The Great Lakes State's move comes at a time when researchers from the Insurance Institute for Highway Safety recently concluded that legalizing marijuana for recreational use is having a negative impact on the road safety.

Michigan previously legalized marijuana for medical use, but now joins California, Oregon, Washington, Alaska, Colorado, Nevada, Massachusetts, Vermont, Maine, and Washington, D.C., in decriminalizing the substance for recreational purposes.

Michigan's move comes on the heels of new data that shows a marked increase in auto accident insurance claims in certain states that have legalized recreational marijuana. Specifically, according to the institute and Highway Loss Data Institute, Colorado, Nevada, Oregon and Washington saw a 6% spike in insurance claims since retail sales of marijuana became legal.

At the same time, police-reported crashes in Colorado, Oregon and Washington rose after retail sales began. The institute estimates that the states experienced a 5.2% increase in the rate of crashes per million vehicle registrations, compared with neighboring states that didn't legalize marijuana sales.

"As more and more states make this transition, society is making tradeoffs," said Tom Coffey, senior vice president of sales of Merchants Fleet Management. "No doubt this has become a civil liberties or personal freedoms issue. However, there is little to no upside from a business productivity or driver safety perspective. It's a hard argument to make that somehow we are safer on the road and employees are more efficient if they are driving while buzzed."

Michigan passed Proposal 1, which creates a system to regulate, tax, and sell recreational marijuana to adults in the state.

Retail sales in Michigan are projected to begin in 2020, with recreational marijuana poised to become a big business. Over the first five years, the state would generate a combined $520 million in revenue from a new 10% marijuana excise tax and the existing 6% state sales tax, according to an analysis reported in the Detroit News.

Revenue from the excise tax would be divided between roads, schools and local governments, notes the report.

In related news, Utah and Missouri voters legalized medical marijuana on Nov. 6. They join 30 other states that have previously legalized the drug for medicinal purposes.