When your teen enrolls in driver's ed, you probably worry about lots of things-schedules and transportation, for instance. Can your child squeeze in driver's ed between other classes, basketball practice, band rehearsal, a part-time job and everything else? Can he find a ride or catch a bus or subway? If not, can you arrange convenient drop-off and pick-up times?

You also think about how much this program will set you back. Even if you're lucky enough to live in a district that offers high school driver's ed, you may still have to pay a fee. Furthermore, if the local school doesn't offer a program, then you have to look at neighboring districts.

But fess up-probably the last thing you worry about is what you need to do beyond serving as chauffeur. In fact, experts agree that your teen's safety depends mostly on you and not on his or her formal driving instructor. "Driver education is not a vaccine against car crashes," says Larry Lonero, principal of Northport Associates, a research and consulting firm specializing in safety training and research. "Regardless of how good the instructor is, parents must take an active role. The more involved you are, the lower the risk will be."

Driving represents the single most dangerous activity your child will undertake, period. Traffic crashes kill more teenagers every year than guns, drugs, AIDS and suicide combined. Facing that stark statistical reality, you can't afford to sit on the sidelines and rely solely on the training your child gets from an instructor, no matter how qualified or competent.

Besides, unlike quadratic equations or the plus-perfect verb tense, driving is a high school subject that you actually know something about. You've done it every day of your entire adult life. New York State requires 16- and 17-year-olds to log at least 20 hours of supervised behind-the-wheel practice while they have a learner's permit. Experts offer the following advice for making the most of those 20 hours-and beyond.

•  Act like a role model

If you preach safety to your teen, you had better walk the walk, not just talk the talk. "By the time teens start to take driver's ed, they've already learned a lot about driving habits-both good and bad-from their parents," says William Van Tassel, PhD, manager of driver training operations for AAA National.

Do you yak on your cell phone, swear at other drivers, tailgate, ignore the legal speed limit or squeeze through intersections just as the light turns red? Then why expect your kid to drive differently or to listen to your safety advice? Teens have exquisitely fine-tuned radar for hypocrisy, especially from parents.

To become a good role model-and to reinforce your coaching credibility-clean up your act behind the wheel. If your techniques need work, then brush up by taking a course from the Club's Driver Improvement Program (516/873-2381 or AAA.com/safety).

• Plug in to the school's curriculum

Check out the syllabus or course outline from your teen's driver's ed class, and take time to read the textbook. Pay particular attention to how the course teaches risk management, not merely manipulation of the controls.

"Everyone has to learn how to control the vehicle," says Frederik R. Mottola, executive director of the National Institute for Driver Behavior and professor emeritus at Southern Connecticut State University. "But perceptual guidance is the foundation for good decision-making, and that's the most important part." For example, Mottola has developed a curriculum that guides students through a matrix in which they find a potential problem or conflict, consider options for solving it, then make the optimal choice to control risk.

Whatever the process for risk management, knowing where to look, identifying potential risks and taking corrective action form the building blocks for behind-the-wheel safety. You want to reinforce those skills as specifically as possible in your coaching sessions. Before you do, however, you need to know how your teen's driver's ed curriculum teaches them.

• Set a schedule, and stick to it

Your child probably has set aside a regular time to practice a musical instrument, finish homework, and do household chores. Why should driving practice take a backseat? It requires a firm commitment from both you and your teen.

Most experts agree that a student driver shouldn't spend more than 45 minutes behind the wheel at a time. Longer sessions only make kids tense and fatigued, and the law of diminishing returns sets in.

• Focus on one objective per session

Ideally, your practice sessions should reinforce the skills that your teen has learned in that week's class. That requires good communication between the home and school." A good driver education program will co-ordinate closely with parents for practice," emphasizes Mottola. "There should be at least two or three contacts between the instructor and the parents as training progresses. The school should guide the parent as to what kinds of skills are being taught."

Shooting a foul shot, serving a tennis ball or playing a scale on a keyboard demands specific technique reinforced by repetition, over and over again. The same goes for navigating urban intersections, changing lanes on an expressway, negotiating turns and other driving skills. Executing such maneuvers safely and consistently involves a series of specific steps. Emphasize those steps as outlined in the student's textbook or other materials, and reinforce them by repetition throughout the lesson.

•  Map out your route in advance

Rather than choosing your route ad hoc, keep the session's objective in mind and plan accordingly. Knowing where you're going beforehand not only lets you choose the best driving environment for the targeted skill, but also takes a bit of pressure off your teen. As Van Tassel notes, "Not having to worry about navigational details frees up students mentally to practice the particular skill for that day's session."

•  Encourage decision-making on the move

To keep your teen fully engaged- and to reinforce the decision-making process-take the opportunity to play a "what-if" game every so often. What if the car immediately ahead braked suddenly? What if that pedestrian stepped off the curb and onto the street? Used sparingly, such exercises help a new driver spot potential hazards and plan appropriate countermeasures.

• Keep feedback short and sweet

As any high school coach will tell you, praise works way better than criticism with most teens. Look for opportunities to offer positive feedback and make it as specific as possible. "You controlled your speed well on that turn" or "Smooth stop!" reinforces a particular technique and gives the student a sense of accomplishment.

When necessary, a gentle reminder will usually serve to correct a mistake. Do you notice the speedometer creeping up and your knuckles turning white? Resist the temptation to shout "Slow down!" Instead, ask "What's the speed limit here?"

Above all, avoid overwhelming new drivers with information. They have enough to think about while they're behind the wheel. If a situation demands a long, complex explanation, pull over and talk it out.

• Consider a contract

Of course, your involvement in driver education doesn't stop at behind-the-wheel practice while your child has a learner's permit. It also extends to spelling out your teen's responsibilities in exchange for driving privileges and agreeing on the consequences of not meeting those responsibilities.

The state's current graduated-licensing laws already set certain requirements for teens after they get a junior license-mandating seat belt use, limiting the number of adolescent passengers, setting driving curfews, emphasizing zero tolerance of drugs and alcohol and rescinding the license after a serious traffic ticket, etc. For more information, visit www.nysdmv.com.

A driving contract between you and your teen can go further. For instance, some parents negotiate even stricter limits on peer passengers and night driving (two of the most significant factors affecting teen crash rates) until the new driver logs a certain number of hours or miles. Many insist on their teens sharing the cost of gas, maintenance and insurance as a way to teach financial responsibility. Or they link driving privileges to academic performance. Depending on your particular circumstances, you might even want to limit driving distractions, such as talking on a hands-free phone or changing CDs. The consequences for violating any of these agreed-upon strictures could range from doing extra chores to limiting the number of driving hours per week to losing driving privileges altogether.

Whatever you and your teen negotiate, spell out the terms clearly and stick to them. You can find more suggestions and sample parent-teen contracts on AAA's Web site. For more information on the contracts and other driver training tools, visit AAA.com/safety.

"Most teens-and most parents, for that matter-think of driver training as just another hoop to jump through," says Mottola. "In fact, it's the one opportunity we have to acquire habits of risk management that will last a lifetime." By staying involved with your teen's training, you can seize the opportunity, not squander it.