The best and worst states to have a teen on your car insurance

teenage drivers
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Parents are right to dread the day when their teenager gets behind the wheel.

The average married couple will pay 80 percent more for car insurance when their teen is added to the policy, according to a new report by insuranceQuotes.com. Teenage boys and 16-year-olds, girls and boys, are the most expensive additions, nearly doubling their parents' rates.

But location can also make a huge difference in how much a teenager's insurance costs. Six states don't allow insurance companies to use gender to determine rates, and one state—Hawaii—prohibits including age or length of driving experience in the calculation.

New Hampshire is the worst state to insure a teenage driver, with a rate jump of 115 percent. Wyoming, Illinois, Maine and Rhode Island also see policy costs double when a teen is added.

There may be a silver lining in the report—the average cost of insuring a teen is down slightly since 2013, when the average insurance bill increased by 85 percent.