Check Up: Study finds graduated licensing systems, decals help reduce accidents

Since the mid-1990s, the rate of vehicle crashes for teenagers has plunged thanks to graduated driver licensing laws that restrict driving privileges until teens gain experience behind the wheel.

"But even with these graduated driver licensing systems, crashes are still the leading cause of death and disability in teens," said epidemiolo-

gist Allison Curry, director of the Center for Injury Research and Prevention at the Children's Hospital of Philadelphia.

A new study led by Curry suggests that states can make their graduated licensing systems even more effective by requiring young drivers to display a teen driver decal on their vehicles.

The study analyzed licensing and crash records in New Jersey, which in 2010 became the first - and so far, only - state with a decal provision. The theory is that flagging novice drivers makes them more compliant with the rules, and easier for police to identify when they drive late at night or have too many passengers.

Crash rates among teens with probationary licenses fell 1.8 percent per year in the four years before the decal provision, and 7.9 percent per year in the two years afterward, the study found. For probationary-licensed drivers aged 18 and 19, the crash rate decline was even more dramatic - 13 percent per year.

The monthly crash rate for probationary licensees fell from 143 per 10,000 drivers in the pre-decal period to 127 per 10,000 drivers in the post-decal period.

Bottom line: 3,197 crashes were prevented, the researchers estimated in their paper, published this month in the American Journal of Preventive Medicine.

While they expected to see an effect, "we were a little surprised by the magnitude," Curry said."It wasn't accomplished through a public health campaign. And compliance with the decal provision was less than ideal."

The law says the reflective red stickers - $4 for a pair - must be put on front and back license plates. Scofflaws, if caught, can be fined $100.

New Jersey already had an unusually comprehensive graduated licensing system and the highest minimum probationary licensure age of 17.

At age 16, Jersey teens can get a learner's permit, but it allows only supervised driving for at least 180 days. At 17, they can get a one-year probationary license, which bans driving between 11 p.m. and 5 a.m.; all cellphone use, even with a hands-free feature; and more than one passenger unless a parent is in the vehicle. New Jersey applies the rules to any new driver who seeks a license up to age 21.

Although teen driver decals have been standard for years in Australia and other countries, researchers couldn't isolate the effect of the tags from other restrictions, Curry said.

New Jersey's new provision "was one of the first opportunities to tease it out," she said.

Her team made mathematical adjustments to eliminate other factors that might affect teen crash rates, such as gas prices and crash trends among licensed drivers in their twenties.

Although Pennsylvania doesn't have a decal provision, it recently adopted the nation's toughest supervised driving rule, requiring teens who are on learner permits to complete 65 hours of supervised driving, including 10 at night and five in bad weather.

Massachusetts and New York are considering adding decal requirements; Delaware has a voluntary decal program.

"Based on these findings, we think other states should at least consider adding decals," Curry said.