Michigan’s graduated driver licensing system has seen the number of 16-year-old drivers injured or killed in vehicle accidents drop dramatically over the past decade, and is proving so successful that other states are not only considering implementing similar systems but also introducing tougher rules and restrictions. One bill that appears to be gaining popularity is to limit the number of young passengers a teenage driver can have riding with them. Another would prohibit 16-year-old drivers from using mobile phones while at the wheel.

The new bills were instated after new crash data showed that in Michigan fatalities in vehicle accidents caused by teen drivers had fallen 41% since the graduated driver licensing system was introduced. Fatalities for drivers in all age groups declined over the same period by only 28%.

The licensing system requires teenagers to pass through two levels of training and restricted driving before applying for a full license, reports The Detroit News.

There has been a great of deal of opposition towards the bill to limit the number of passengers a teenage driver can carry, as there are drivers with young families and it would mean an end to giving friends a lift to school. However, only last week information was released by the National Highway Traffic Safety Administration (NHTSA) that showed more than two thirds of all teenagers killed in vehicle accidents at night were not wearing a seatbelt, and one of the reasons cited was peer pressure from fellow passengers.