The National Association of Insurance Commissioners (NAIC) notes that US consumers paid a combined average premium of $939.19 for a year’s worth of auto insurance coverage in 2003, and paid $885.66 in 2002. Combined average premium is the average premiums for liability, collision and comprehensive added together.

The national average premium in 2006 was $1,916, in 2007 that average has dropped to $1,896, a slight decline.

The last major study by the NAIC of insurance was done in for 2002/2003 and the cheapest states tend to be Iowa, Idaho, Ohio, Wisconsin and North Dakota. In 2003 consumers in IA paid on average about $679 in insurance premiums compared to the national average of about $914.

The average auto insurance premium for residents in Idaho was $711 at this time and $752 in Ohio. Drivers in Wisconsin on average paid $693 and drivers in North Dakota paid only slightly more at $695.

More populated states of New Jersey, New York, Massachusetts and the District of Columbia (D.C.) have been known to be some of the most expensive states to insure a car in. In 2003 the average NJ rate was $1365, New Yorkers were paying an average of $1313, MA residents $1134 and DC drivers $1277.

The NAIC did another study that showed estimated average expenditures for private passenger automobile insurance by state for 2001 to 2005. This study provided approximate measures of the relative cost of automobile insurance to consumers in each state.

To calculate average expenditures the National Association of Insurance Commissioners assumed that all insured vehicles carry liability coverage but not necessarily collision or comprehensive coverage. The average expenditure measures what consumers actually spend for insurance on each vehicle. It does not equal the sum of liability, collision and comprehensive expenditures because not all policyholders purchase all three coverages.

This research found the five least expensive states to be North Dakota (average expenditures $554), Iowa ($555), South Dakota ($565), Idaho ($583) and Kansas ($590). The most expensive states were found to be New Jersey ($1184), D.C. ($1182), New York ($1122), Massachusetts ($1113) and Louisiana ($1076).

Auto insurance is more expensive in urban areas because of the higher density of traffic, increased likelihood of theft and vandalism, and greater incidence of fraud so while the states listed above may be the most and least expensive as a whole there are specific cities throughout the United States that are found to be the cheapest or most costly and are found in other states.

A study of 2007 car insurance rates by Runzheimer International found Detroit, Michigan to be the more expensive city to have auto insurance coverage in at a cost of $5027 and Eau Claire, Wisconsin to have the least expensive insurance with rates of $869. This was as of June 2007 and assumed $100,000/$300,000/$50,000 liability limits, collision and comprehensive with $500 deductibles, and $100,000/$300,000 uninsured coverage.

Other expensive cities were Philadelphia, PA ($3779), Newark, NJ ($3381) and Los Angeles, CA ($3027). Other cheap cities to insure a vehicle were found to be Norfolk, VA, ($952) Raleigh, NC ($966) and Bismarck, ND ($989).

Click here to view an interactive map of the car insurance laws in the United States. Look up individual state requirements for minimum insurance and follow the state links to get important information about insurance in each state. Then you can get a inexpensive car insurance quote here with us.