Gov. Arnold Schwarzenegger has signed a bill into law that requires young drivers to turn in their keys an hour earlier.

The new law, previously AB1474, requires anyone in the first year of their provisional driver’s license to be off the road from 11 p.m. to 5 a.m.

An exception would be made for young drivers accompanied by a licensed driver who is at least 25.

Existing California law permits provisional drivers out on the road until midnight.

According to the Insurance Institute of Highway Safety, 42 percent of the nation’s fatal crashes involving teen drivers in 2003 occurred between 9 p.m. and 6 a.m., despite the fact there typically are fewer teens behind the wheel during those hours than during daytime.

The new law also bars 16- and 17-year-old drivers from transporting passengers under age 20 during the first year licensed, unless accompanied by a licensed driver who was at least 25. Under existing law, that restriction lasts for the first six months licensed.

Violators would face a $35 fine or eight to 16 hours of community service.

Teens traveling to or from work, driving for medical “necessity” or transporting immediate family members are exempt from the new rules.

Police are not allowed to pull over a driver on suspicion of violating the provisional driving law. Teens could only be cited if pulled over from some other traffic violation, such as speeding or running a stop sign.

The new rule takes effect Jan. 1.