All you need to do to understand why teen drivers crash more than any other age group is to wait near a high school for the final bell to ring, right?

In 30 seconds, you'll hear engines hum, tires squeal and brakes screech. And If you're past 40, you'll know – you'll positively, definitely, absolutely know – that the main reason that kids are killed in cars at a rate four times greater than we are is that they're too aggressive behind the wheel.

And you would be wrong.

A recent study of fatal teen crashes showed that common driving errors – generally related to a lack of experience – contributed most to serious crashes. And at 21 percent, the leading error was failure to scan the traffic ahead. Another big error was the one that trips us all up, regardless of age: Distraction – either from something inside or outside the car — contributes to 20 percent of serious teen crashes.

Researchers for the Children's Hospital of Philadelphia's Center for Injury Research and Prevention concluded that aggression, poor weather and drowsiness were not primary factors in most teen collisions.

"This study helps dispel the myth that most teen crashes are due to aggressive driving or thrill-seeking," said lead researcher Allison Curry, Ph.D. "Promoting safe driving skills is as important as preventing problem behaviors."

Chief among these skills is scanning ahead of immediate traffic and looking side to side to anticipate trouble before it occurs. Scanning is considered a higher-level skill that's developed over time, so driving schools generally don't spend much time on it during the six hours of instruction mandated by state law for young driver-permit holders.

"The emphasis at too many driving schools is to get kids through training as quickly and as cheaply as possible," said Pam Fischer, a traffic safety consultant who formerly ran the state Division of Highway Traffic Safety. "Teens would probably be better drivers if the emphasis was on more intensive training."

Instead of training, Fischer's tenure in the traffic safety division produced several teen driving reforms that emphasized law-enforcement.

New Jersey's 10-year-old Graduated Driver License law, for example, now requires young probationary drivers to carry no more than one teen passenger unless an adult is in the car, and a red bumper decal now identifies drivers who have not yet completed the GDL training phase. The decal probably contributed to the decline in teen traffic deaths in New Jersey. Seventeen teen drivers were killed during the nearly 12 months since the new laws took effect May 1 compared to the 36 teen drivers killed in 2009, the last full year under former GDL standards.

Likewise, tickets for GDL violations approach 1,300 monthly under the decal reform compared to 900 prior to reform. Presumably, police can more easily spot GDL violators now because of the red teen identifier, the first of its kind in the nation.

But now that enforcement has been stepped up, is it time to concentrate on driver training?

"Absolutely," Fischer said, "but it's hard to convince parents that it's needed."

"Parents will spend thousands on their kids' tennis lessons and hockey camps," said Dan Gaskill, president of the Driving School Association of America, "but they rarely want to put much money into driving lessons."

Nearly all high schools gave up behind-the-wheel driver training more than 20 years ago. The great majority of formal training is now conducted by 200 driving schools sprinkled throughout the state, including Gaskill's Princeton Driving School in Mercer and Hunterdon counties. The cost for six hours of training to meet state requirements generally runs from $250 to $500.

If road safety advocates had their way, the requirement would be boosted to 10 or 12 hours. Modest additional training wouldn't turn most teens into highly proficient drivers, Gaskill said, but it could enable them to focus on more sophisticated driving techniques, such as scanning.

The real challenge, Fischer said, is to show parents the importance of getting as much involved in their kids' driver training as they are in their overall education.

Two bills now in committee are designed to do that. One would require parents or guardians to log 50 hours of practice driving time with their teens before they can take road tests to obtain licenses. Another would require parents to attend high school driver-ed orientation courses with their children.

"When parents attend these classes, they're often surprised by the lessons they learn," Fischer said.

One of those lessons: "Crashes kill more teens than anything else," she said, "and a good way to prevent fatal crashes is training." Learn more at northjersey.com/gdl.