Brittany Hawthorne, 17, another Southfield-Lathrup senior, said there may be emergency situations where she'd have to drive more than 80, possibly to accelerate to avoid a crash.

Ford's research shows that parents would be more likely to let teens use their vehicles with the system, Sherwood said, and if it gets them the car more often, the number of teens objecting drops by nearly half.

A top official from the Insurance Institute for Highway Safety, a research group funded by the auto insurance industry that is pushing to raise the minimum driving age to 17 or 18, found the key intriguing and said she was not aware of any other manufacturer offering such a feature. IIHS says car crashes are the leading cause of death among teenagers.

"Research we've done has shown that speeding is a major factor in teen crashes, especially novice teen drivers," said Anne McCartt, the institute's senior vice president for research. "So I think a system that tries to correct the speeding behavior has the potential to improve safety."

More than 5,000 U.S. teens die each year in car crashes. The rate of crashes, fatal and nonfatal, per mile driven for 16-year-old drivers is almost 10 times the rate for drivers ages 30 to 59, according to the National Highway Traffic Safety Administration.

Several U.S. auto insurers have begun offering in-car cameras or global positioning equipment to help parents monitor their teens' driving behavior, in the hope of reducing the number of crashes.