Parents who want to improve their kids’ safety behind the wheel already know enough to warn them against yakking on phones, sending text messages, stuffing cars with too many passengers, going faster than the law allows and, of course, ingesting anything that makes them forget — even for a moment — that driving is deadly serious.

These warnings make sense because crashes kill more teens than anything else and distracted and drunken driving are leading causes of traffic deaths. But how many of us ever warn our kids about the highly deceptive danger that many of us associate with driving pleasure?

That’s listening to loud music.

Yeah, I know: Restricting heavy metal or hip-hop amounts to fascism. But before you roll your eyes and turn to the sports pages, please consider one of the findings uncovered in a 2008 study by Erie Indemnity, a Pennsylvania insurance carrier:

A whopping 93 percent of teen drivers play loud, distracting music behind the wheel.

And then there’s this disturbing news uncovered in 2001 by Canadian scientists at Newfoundland’s Memorial University:

Reaction time slows as much as 20 percent when someone is subjected to loud volume, a potentially fatal delay for motorists driving even at modest speeds.

I’m supposed to know things like that, but shamefully I didn’t. I felt less shameful a couple of weeks ago, though, when I mentioned them to U.S. Transportation Secretary Ray LaHood at a safe-driving event in Yonkers. The response from the man who’s leading the nation’s anti-distracted-driving campaign was little more than a puzzled stare.

Actually, I only know this stuff because of a young lady from Emerson. "Few people recognize the dangers of loud music," Jennifer Budres explained.

To be fair, Jennifer has an advantage over know-it-alls like LaHood and me. We got our driver’s licenses while Bacharach and David were still churning out hits. Jennifer, 17, got hers a few months ago around the time she received an assignment from her television production teacher, Ava Annese, to find a topic for a teen-driving media campaign.

"I remembered that when I’d been practice driving with my mom, my mind would wander whenever I blasted my music," she said. "I realized I wasn’t concentrating on my driving."

The Emerson High School junior, who wants a career in television journalism, teamed up with another junior — Jake Williams, also a budding broadcaster — who recalled getting so wrapped up in a loud song "that I blew through a stop sign." Luckily, nobody was hurt but the two recognized that others in their age group were probably getting distracted by heavy metal and hip-hop, too.

Jennifer jumped on the Internet. Among her findings:

* Loud music prevents drivers from hearing sirens and horns
* Nearly all states treat loud music as an annoyance offense, not a distracted-driving violation.
* A 1995-99 Highway Safety Research Center study showed that adjusting a car radio or CD player was the second most prevalent in-car distraction.
* Car radio volume typically exceeds 100 decibels, considerably louder than the maximum sustained exposure recommended for humans.
* A Ford Motor Co. system allows parents to limit audio levels in young drivers’ cars to 56 percent less than maximum volume.

This research was enough to make Emerson High one of 19 finalists in the New Jersey Brain Injury Association’s "U Got Brains" high school teen-driving safety contest. Emerson students are conducting their own research and creating a public service announcement video called "Victims of Volume" that raises public awareness about the dangers of loud music.

Should it be outlawed?

Jennifer isn’t so sure. "For now," she said, "we’re just suggesting that drivers keep their car radio volume about halfway from the loudest setting."

But will teens who have been blasting car radios since the Big Band era voluntarily pull back on the sounds they love?

"Some say they should be allowed to play music any way they want," she said. "But once you show them the evidence about the harm it can do, they start to get the message."

Road Warrior runs Wednesday, Friday & Sunday. E-mail cichowski@northjersey.com.