I remember when the states started raising the legal drinking age back up to 21. Congress essentially forced them to--it passed a law in 1984 providing that they would lose a portion of their highway funds if they continued letting 18-year-olds buy alcohol. By 1988, every state had complied. Barely a decade after most of them had lowered the drinking age, in an attempt to slake the powerful Baby Boom thirst, they had taken the privilege away again. They did it just in time to turn off the tap for the so-called Generation X teenagers, born after 1965 and just then starting to care about such things.

Still, it seemed like a sensible enough idea, at least to most people who were over 21 at the time. Many had a hard time understanding why the drinking age had been lowered in the first place. What was interesting to me, though, was the rationale. Sponsors of the Uniform Drinking Age Act argued that the rules had to be rewritten because legal drinking by teenagers was causing too many traffic accidents. No doubt this was true. It seemed pretty obvious, however, that they were choosing the wrong strategy. It wasn't the drinking age that needed to go up. It was the driving age. Keeping kids off the highways until they were a little older would be a far more efficient way to save lives than denying them the right to buy beer.

I actually said this on a couple of obscure talk shows, but I wasn't so naive as to think it would happen. The issuance of an unrestricted driver's license at age 16 was too important a rite of passage to be tampered with by any legislature, even for the purpose of avoiding thousands of preventable deaths every year. Or so I was convinced.

I didn't expect that lowering the drinking age alone would make much difference. Actually, it did make some difference. Over the course of the 1990s, the number of teenage drivers in the United States remained almost exactly the same. But the number of traffic fatalities involving teenagers decreased 10 percent. Fatalities in which the police found evidence of intoxication went down 38 percent.

On the other hand, traffic accidents remained a terrifying problem. They are still the leading cause of death in this country for people between the ages of 15 and 20--accounting for more than one-third of all such deaths, in fact. Teenagers represent about 7 percent of all licensed drivers, but 14 percent of all drivers who die on the road. At one time, it was argued that formal driver education programs might make a dent in those numbers. But by the mid-1990s, it was becoming clear that driver's ed made virtually no difference at all.

And so, states began to consider the unthinkable. They began to raise the driving age. At least in a timid sort of way. They began to pass graduated licensing laws, under which young novice drivers move in stages from highly restricted learner permits to full adult privileges. Five years ago, very few people in this country even knew what graduated licensing was. Now, more than 40 states have it in one form or another.

The laws differ, but there are three essential components. One is a period in which teenage learners can drive only with an adult in the car. Second is a night-time curfew hour, after which they cannot drive at all. Third is a limit on the number of passengers they are allowed to carry.

I was initially skeptical of this as well. Under the old system, kids in a majority of states weren't even allowed behind the wheel of a car until they turned 16. Now, they are beginning to drive even earlier-- at 15 or 15 1/2 in most places, albeit with the requirement that a grown-up sit next to them. If the goal was to raise the threshold, it seemed odd to start by lowering it.

But I underestimated the importance of graduated licensing, just as I had underestimated the Uniform Drinking Age Law in the 1980s. There are statistics now on the impact of graduated-license laws over the past five years, and they are pretty impressive.

Statistics compiled by the Insurance Institute for Highway Safety suggest that a state that passes a graduated-license law can expect a reduction of 23 to 27 percent in teenage road fatalities.

Some have reported even more dramatic results. Pennsylvania switched to a graduated system in 1999 and reported after one year that teenage fatalities had declined by 70 percent. Georgia, with a relatively weak law, nevertheless found that 16-year-olds had ceased to be the most dangerous drivers on the road. Eighteen-year-olds had claimed that title.

Of course, it's not that 16-year-olds had all become careful drivers. It's that the strictures of the new law were preventing them from racking up as many miles. But so what? Lives were still being saved. "Something's going right out there," a National Highway Traffic Safety Administration official commented last year, "and we have every reason to think it's graduated licensing."

Admittedly, the limits on carrying passengers have produced bizarre side effects. Wisconsin, for example, forbids junior drivers to carry more than one other person in the car. Kids who used to drive to school in one vehicle with several classmates now have to split up into two or three cars, putting that much more traffic on the road and creating a desperate search for parking spaces. Montana legislators enacted a two-passenger limit, only to find themselves under attack from an unexpected source: fundamentalist Christians, who claimed that the rule prevented double-dating, which they saw as the best protection against sexual experimentation.

The anecdotes are endless, but once again, the statistics are pretty conclusive. A study conducted in Utah over four years found that a teenager with even one passenger in the car ran a 70 percent higher risk of accident. According to the Insurance Institute for Highway Safety, one passenger will double the risk of a fatality; two or more will increase it five-fold. (The opposite is true for adults, by the way. Driving alone is more dangerous for them.)

Then, too, the curfews penalize some people for the wrong reason-- such as high school rowers who have to leave for crew practice before the restrictions are lifted at 5 a.m. They also force parents to stay up late so they can rescue their kids who are still out when the curfew hour strikes.

Actually, the curfews may be the biggest loophole in the laws as they have taken effect so far. Most states have opted to prohibit "intermediate drivers"--those just past the learner stage--from being out on the road beyond a specified hour. But they've been pretty half- hearted about it: Most of them have opted for either midnight or 1 a.m. Studies show that most wrecks occur long before that time. In order to have much practical effect, says the Insurance Institute for Highway Safety, the curfew hour needs to be 9 or 10 p.m.

What would make even more difference, of course, would be laws that move the whole process back a significant number of months. The Insurance Institute model statute calls for a six-month learner permit, starting at age 16, followed by a year and a half with curfew and passenger limits, and full-fledged licensing only at 18. That doesn't exist anywhere right now.

The reason it doesn't exist isn't the strength of the adolescent lobby. It's a fact that in suburbs all over America, a 16th birthday doesn't just represent freedom for the child. It ushers in a new era of freedom for the adults who have been driving to school and to soccer practice and to the mall on Friday night for a decade or more. They wouldn't want to give it up. It isn't the kids who are the main obstacle to safer licensing laws; it's their parents. That's the reality that almost everyone understands but many prefer not to discuss.

One Maryland mother acknowledged it in an article in the Baltimore Sun last year. "For a parent who has been playing chauffeur for 17.5 years," she wrote, "the impulse suddenly changes from 'You are not driving until I say you are ready' to 'If you had your license, you could do your own errands.'"

Teenagers can be even more blunt than that. "The reason we want to drive so bad," one Texas high school student explained recently, "is that our parents are sick of taking us places." It may not be pleasant to admit it, but she has a point.

The point, however, isn't that 21st-century parents are indolent and self-centered, even though some of us are. The point is that 21st- century America is a country designed and organized for the use of automobiles. The majority of us live in communities where it is hard to get around without driving. That imposes a natural restriction on how far we can go in rewriting the rules, even in the interest of safety.

It is no coincidence that the one jurisdiction in America that makes it extremely difficult for anyone under the age of 18 to drive an automobile is New York City. Parents in New York are largely spared chauffeur duty. Their kids can take the subway. It makes a big difference. If we all followed New York's rules, not only would our streets be safer but we'd get to see a little more of our 16- and 17- year-olds. They wouldn't be in a different suburb 15 miles away on a typical weekend night.

Perhaps we should have thought about that when we built the interstate highway system a generation ago. Then again, it wouldn't have made much difference. We created a car-dependent culture because we had the space, the money and the gasoline. It's unrealistic to think any degree of prescience about the long-term consequences would have dissuaded us.

In any case, the reality is that we foreclosed most of our options a long time ago. About all we can do now is try to save some lives at the margin with cumbersome but effective tools like curfew hours and passenger restrictions. Sometimes I think even the existence of those is a minor miracle.