Little red decals on New Jersey license plates have stirred up plenty of controversy. But according to a new study, they've also prevented more than 1,600 crashes among teen drivers.

Researchers at the Children's Hospital of Philadelphia crunched the numbers for the first year that New Jersey's probationary drivers were required to display red stickers on their license plates.

"And our main finding was that the decals did seem be doing what they were intended to do," said CHOP epidemiologist Allison Curry.

Curry's team of researchers found that crashes among young drivers fell 9 percent, while police citations on related restrictions increased 14 percent. You can read (and annotate) the full report below. It was published this week in the American Journal of Preventive Medicine.

Better behavior and easier enforcement

The decals make it easier for police to enforce restrictions related to New Jersey's graduated driver licensing law.

Those restrictions prohibit teens from driving after 11 p.m., having more than one passenger in the car and using electronic devices.

While nearly all states have similar rules, New Jersey is the nation's first to require an identifying marker.

"Without the decal, police really don't have a way to determine which teen drivers are subject to these important restrictions," Curry said.

She says the decals are also thought to increase compliance with the restrictions, "and may in general make [teens] less willing to engage in risky driving."

"This doesn't just make adolescent drivers safer," Curry said. "It makes all of the people driving on the road with these adolescent drivers safer."

Continued controversy

CHOP researchers call the reduction in crashes "significant." But that doesn't mean the results are tamping controversy surrounding the law.

"One life saved would have made this law worthwhile," said Assemblyman John Wisniewski, D-Middlesex. "This many crashes avoided makes it a tremendous success."

The CHOP study notes attempts to repeal the law by Republican lawmakers. State Sen. Christopher "Kip" Bateman, R-Hunterdon, Mercer, Middlesex and Somerset, says the law still needs fixing.

"We also must consider the reality and prevailing parental concerns that red license plate decals make teenagers vulnerable to predators, kidnappers and other offenders," said Bateman.