From the passenger's seat, Andrew B. Burkhardt had nothing to stop the car but his voice.
"Stop!" Burkhardt shouted on instinct, just as his 16-year-old son, Clark, pressed the brake.
The family's 1998 Nissan Maxima came to rest safely behind another car that had stopped in the road.
It was a tense moment in the long ordeal of building Clark's skills and honing his road judgment as he practiced driving on his learner's permit.
I'm sorry for yelling, Burkhardt told his son. I'm trying to let you make little mistakes, but that seemed like a big one coming.
No, Clark replied. I saw it right when you yelled.
Driving experts sympathize if parents find themselves slamming the invisible brake pedal on the passenger's side of the car -- what driving school teachers call "the air brake."
It's common for parents to "get a little anxious and excited when the student is coming up behind a car too fast," said Brad Hays, a veteran driving instructor at Kern Driving School, in Bakersfield, Calif. "They don't have a duel brake like we do" in a driving school car.
Burkhardt admits that practicing on the road with his son is at times "emotionally taxing" for both of them.
But few things a parent does are more important, insisted Bud Chauncy, the president of the Driving School Association of the Americas Inc.
"I don't think most parents realize that 15 to 18 teens die in car crashes every day," said Chauncy, also a driving instructor and the owner of First Class Driving School in Bossier City, La. "We wouldn't send our kids to a piano recital if they didn't have enough practice time."
"If your son or daughter is not prepared to drive, they won't be booed" for a bad performance -- they could be hurt or killed, Chauncy warned.
Yet surveys show that only 17 percent of parents in California, for example, complete the full 50 hours of road practice with their teens required by state law.
Fifty hours of practice with an adult in the car is the minimum, in addition to any professional instruction required by the laws of your state, the experts say.
One common problem is that many parents see their kids confidently controlling an automobile and assume they can drive. But the concern with teen drivers is mental, not physical, according to Chauncy.
"The vast majority of crashes [among teens] happen because of lack of experience and improper perception of risk," said Chauncy.
Burkhardt's insurance company told him as much: While his son has a learner's permit and is driving with an adult, the insurance rates don't go up.
But once his son gets his license?
"As soon as the adult judgment is removed from the car and 16-year-old judgment takes over, the rates soar," Burkhardt said.
To smooth out the bumps on the road to making your teen a safe driver, Chauncy and Hays offered some strategies and tips.
The Burkhardts started their practice the right way, according to the experts -- in empty parking lots near their home in Cranston, R.I., to allow Clark to develop a feel for how a car turns and brakes. From parking lots they graduated to cemeteries, where speed limits are 5 or 10 mph, and the residents don't complain about new drivers.
"Then we worked on the streets," said Burkhardt. "City driving in some ways is tougher than highway driving, but the consequences of a mistake are smaller. We haven't yet graduated to the highway."