Data show that teenagers are risky drivers who are very expensive to insure, according to a new report from insuranceQuotes. U.S. families who add a young driver to their existing auto insurance policy will see an average annual premium increase of 79 percent. The good news is that the average premium increase for teen drivers is lower than in 2013, when the increase was as high as 84 percent. In Iowa, the average premium increase for adding a teen driver is 89 percent. “Regardless of the costs to insure your teen driver, safety is the No. 1 priority,” said Laura Adams, senior insurance analyst for insuranceQuotes. “We suggest parents educate teens on the dangers of driving, especially when it comes to texting while driving, or driving under the influence. Two other tips Adams suggests are installing monitoring technology in your car and having your teen sign a contract of safe driving with strict enforcement of the consequences for violating it.