By the time 16-year-old Caroline Groom got her driver's license Oct. 3, she had spent a year deluging her father with e-mails about the makes and models of cars she'd like to have -- including her dream vehicle, a Jeep Cherokee. At first, her father resisted, figuring he'd share his car with her and take Metro to work a couple of days a week from their home in Arlington.

But after "a couple of bad fights," Caroline said, he gave in. "It was kind of a matter of wearing him down," she added. Caroline didn't get her Jeep, but two weeks ago, her father bought her a new silver Subaru Legacy.

Nearly every culture has a recognized turning point between childhood and adulthood, when rules must be learned, tests passed, talismans awarded. In the United States, for the past half-century, the iconic rite of passage for a teenager has been this: You take your driver's test. You get your license. You slide behind the wheel and drive into the grown-up world.

In the past, the car in question usually belonged to Mom or Dad, who handed over the keys with a combination of pride and trepidation. Increasingly, however, the cars teenagers drive are their own. Even parents who hadn't planned to buy their children cars feel pressure to do so -- not only from the new drivers in their household, but also from other parents and from their own busy schedules.

But a recent string of fatal traffic accidents in the area involving young drivers has strengthened some parents' resolve to delay giving a teenager the keys to the highway. Julie Sussman of Centreville long ago decided that her son Chad, 15, will wait until he is 17 to apply for his learner's permit. She said she is baffled by parents who say to their child, "You're 151/2 -- here are the keys to a car."

According to CNW Marketing Research, which tracks national purchasing trends, 41 percent of 16- to 19-year-olds in the United States own cars, up from 23 percent in 1985. The percentage of parents who pay for those cars has also risen. In 1985, 19 percent of teenagers' used cars were paid for by their parents. Today the figure is 40 percent.

One reason parents are willing to spend the money is safety, according to Art Spinella of CNW. If their child is going to have a car, they want it to have air bags and anti-lock brakes. Another reason, he believes, is indulgence.

"Baby boomers are trying as hard as they can to not so much be parents as be friends with their kids," he said. "That translates into buying them a car instead of letting them buy their own car. It translates into buying them a new vehicle instead of getting them a used one and letting them do the work on it."

Not all families can afford cars for their children, and in dense urban areas with subways and limited parking, some teenagers don't want them. But in affluent suburban areas where there is no Metro and bicycle riding is more hobby than transportation, it has become almost odd for a teenager not to have a car.

But many parents are steering a middle course, acquiescing in the car as a convenience for the family and using it as a way to teach responsibility. Gail Harrison of Arlington bought her 16-year-old son, Mike, a 2000 Honda Accord to get to lacrosse and marching band practices. But he had to sign a contract with his parents pledging to drive no more than one passenger under age 18, which is the law in Virginia; to be home by curfew; and to keep his grades up.

"I won't go to sleep until he's home, but from a scheduling standpoint, it does make it easier," Harrison said.

Debra Youngberg, a Centreville mother, has hung a placard by the front door with a traveler's prayer she hopes her children read. She bought her 17-year-old son, Sean, a 2000 Nissan Altima, which he drives to Westfield High School with his 14-year-old sister.

"I watch my life go out the door every morning as they drive away," she said.

Caroline Groom, the new Subaru owner, called getting her license "the highlight of my life." On the first day it was valid, she woke up at 7 a.m. to go driving and found her father, Ted, waiting downstairs to give her a talk about responsible driving and the lasting consequences of a moment's distraction. A friend of his lost his daughter in a car crash, and he had been talking to Caroline a lot about obeying the speed limit and staying off her cell phone.

But like many parents, he accepted that Caroline, a junior at the Madeira School, was going to drive and believes that she wouldn't be any safer riding with friends.

Alan Goodwin, principal of Walt Whitman High School in Montgomery County, where the vast parking lot is full every day, said that many parents buy their teenagers vehicles because an extra driver makes life easier in an age of frenetic after-school schedules.

"Parents do a lot of shuttling at a young age, to music lessons, to sports," he said. "So by the time someone is 16, I think parents find a measure of relief that [teenagers] can drive themselves and can help with the siblings as well."

But some parents are resisting the trend. Long before 15 lives were claimed this fall in teenage driving accidents, Sussman decided that her son Chad, a freshman at Westfield High School, will not get a license -- let alone a car -- when he turns 16 next year. He won't even drive until he turns 17 and becomes an Eagle Scout, his parents told him.

"Everyone I know who has a child who is driving has bought their child a car," Sussman said. "I don't judge them, but they all say to me, 'So, you're going to be getting Chad a car?' and I say, 'No, we're not getting Chad a car.' "

Their reaction: Yeah, right. Sure.

"Why am I defending myself?" she asked. "This is crazy. It should be the other way. I should be saying to them, 'Why are you letting them drive?' "

Tom Fulham, an Alexandria father of three, can sympathize. When his triplets attended T.C. Williams High School, between 2000 and 2003, he did not let them get licenses at 16 or ride in cars driven by other teenagers.

That meant taking the yellow school bus while their friends sailed by in cars. "Nobody wants to ride the cheese bus," said Eleanor Fulham, 20, now a sophomore at Wellesley College. She recalled pressure, especially from kids from wealthier families. "Not, 'Get a car or else,' " she said. "More like, 'You're not cool if you don't.' "

That kind of pressure can weigh on 16-year-olds, whose crash rate is almost three times higher than that of 18- and 19-year-olds.

"They're the worst in terms of overreacting to a surprising situation," said Carolyn Gorman, vice president of the Insurance Information Institute. "Suppose a deer jumps out in front of them. They just don't know what to do."

As teenagers' car ownership rate rises, so does their pickiness. "Just having a car isn't enough in many circumstances," Spinella said. He said that one of the most popular cars among high school students is the Cadillac Escalade, a large sport utility vehicle that averages $50,000. "It's on MTV a lot -- they see a lot of music folks driving them," he said. "It's become kind of a teen cult idol car."

Teenagers are also taking cues from the MTV show "Pimp My Ride," a sort of Queer Eye for the Shabby Car in which hip-hop mechanics restore and customize beaten-up cars, installing such non-standard features as video games, chandeliers, bubble machines and massage chairs.

Although they did not have the same distractions in their youth, many parents cringe as they recall stunts from their adolescence, when air-bags were science-fiction fantasies and seat belts tended to stay wedged between seats. "I have a brother, and I used to drive with him, and it's a miracle we survived," Sussman said. "I am overprotective because I'm frightened."

Chad said he has accepted his parents' decision, although it has caused some ribbing from his friends. "They usually say, 'Ha, ha,' or 'That really stinks for you,' " he said. "But I'd just rather be alive than driving, and I don't really trust my friends on the road."

Still, he waxes dreamy about "Pimp My Ride." In his fantasy, Chad would drive a Corvette. But he is his parents' son, so when the time comes, he said, his ride will be "more likely something like a Volvo."

Caroline Groom, 16, of Arlington got a Subaru Legacy from her father -- in addition to a talk about responsible driving and road distractions.Julie Sussman of Centreville has told her 15-year-old son, Chad, that she won't let him drive until he is 17.