For six years, Insure.com has analyzed and ranked every state in the nation based on average auto insurance costs. And for all of those years, Maine has ranked as the least expensive state.
In Insure.com's latest analysis, Maine's average annual policy premium is $808. The national average is $1,325.
At the other extreme, Michigan ranks as the most expensive state for the third consecutive year. It has an average annual policy premium of $2,738.
The factors that make Maine the cheapest state include not only the state's relatively few large urban areas — and therefore its relatively light traffic — but also its low percentage of uninsured drivers, 4.7 percent.
Maine ranks No. 2 among states with the lowest number of uninsured drivers. That means the state has more drivers to share the risk pool, which drives down costs.
EXPLORE MORE: 10 cars most likely to get traffic tickets
"When everyone is insured, prices go down," as Insure.com puts it.
In Michigan, high no-fault insurance mandates are largely responsible for the high cost of car insurance.
Lori Conarton of the Insurance Institute of Michigan tells Insure.com: "Michigan auto consumers pay more than most states for car insurance due to the state's high medical mandate. Michigan is the only state in the country that requires auto consumers to purchase unlimited, lifetime medical benefits as part of the auto insurance policy."
Insure.com's rankings are based on an analysis of car insurance rates from six large carriers in 10 ZIP codes per state. The rates are based on full coverage for:
A single, 40-year-old male who commutes 12 miles to work each day.
A policy with limits of $100,000 for injury liability for one person, $300,000 for all injuries and $50,000 for property damage in an accident, plus a $500 deductible on collision and comprehensive coverage.
Based on that analysis, the most expensive states are:
Michigan: $2,738 premium
New Jersey: $1,905
Washington, D.C.: $1,773
Rhode Island: $1,608
The least expensive states are:
Maine: $808 premium
New Hampshire: $941
North Carolina: $987
You can find the full rankings at Insure.com.
RELATED: View photos of Google's self-driving cars
How do you feel about car insurance rates in your area? Share your thoughts in our Forums. It's the place where you can speak your mind, explore topics in-depth, and post questions and get answers.