Wayne Cohen spends a lot of time thinking about car insurance. As the father of three sons in their teens and 20s — the most expensive group of drivers to insure — he pays big car insurance bills. And as one of the most aggressive personal injury attorneys in Washington, he has won big car insurance cases.

“Thinking about teenagers on the road is stressful as is, let alone when they are your own kids,” said Cohen. “I can’t tell you how many catastrophic cases I have had over the years where the parents of a teenage driver were underinsured.”

When parents add a teenager to their car insurance policy, their rates are likely to go up an average of 78 percent, according to a study by InsuranceQuotes.com. Based on the average national car insurance bill, that’s $1,028 more. Prices jump even more for boys — 89 percent — but girls are expensive too, raising bills 66 percent.

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