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The number of accidents involving Massachusetts teenagers has dropped by half since the state raised the training requirements for young drivers and boosted penalties for teens who speed or commit other infractions.
That good news gives transportation officials ample reason to crow about the law’s impact. But state data reviewed by the Globe suggests the biggest reason for the drop in crashes may come as a surprise: It is because fewer teens are on the road — not just because teens are driving more carefully.
The number of 16- and 17-year-olds with a Massachusetts driver’s license has plunged by one-fourth since 2006, the year before the Legislature increased training requirements for drivers under 18.
“When they are not driving they are not going to crash,” said Anne T. McCartt, senior vice president for research at the Insurance Institute for Highway Safety.