Matt Rainey for The New York Times

Over the last two decades, researchers have examined the risks faced by young drivers with attention deficit hyperactivity disorder and tried to find ways to help them to learn to drive safely, an issue explored in this week’s Science Times. Now those researchers and driving instructors are finding themselves faced with a new challenge: the growing number of teenagers with Asperger syndrome and other forms of autism, conditions defined by deficits in social skills and obsessive interests that can make learning to drive especially difficult.

“Driving is a social act,’’ says Dr. Jamie Dow, the medical adviser for safety issues for Quebec’s government-run auto insurance and licensing agency. “It involves obeying rules and cooperating with other drivers.’’

For young people with Asperger’s, both parts of that equation can pose problems.

Obeying rules is generally a good thing, but can be taken too far if rules are applied inflexibly or without taking into context into account. For example, does a “Stop at White Line’’ sign mean that the line is where you should stop only if you need to stop — or that you should stop every time you come to it?

And cooperating with other drivers involves perhaps the hardest task for people with Asperger’s: reading nonverbal social cues. On the road, that happens through the “gestures’’ drivers make through the motion of their cars — by changing lanes boldly or hesitantly, for instance. Those motions amount to signals flashed from driver to driver so routinely that most people are hardly aware of the messages being sent about intention or mood.

“There’s some discussion in the field that driving in traffic is like reading a person’s face,” said Lissa Robins Kapust, of the DriveWise program at Beth Deaconess Medical Center in Boston. “The driving scene may be friendly, it may be frenetic, it may be angry.”

Ms. Kapust’s group has made a video, sponsored by the advocacy group Autism Speaks, that examines the trade-offs between the desire for independence and the safety issues for drivers with Asperger’s.

According to a survey conducted by Cecilia Feeley, a project manager at the Center for Advanced Infrastructure and Transportation at Rutgers University, only 24 percent of adults with autism — many of whom described themselves as “higher functioning” — said they were independent drivers, compared with 75 percent of the population as a whole.

But for many people, the surprise is that people with autism are driving at all. “Thirty years ago people didn’t think any kids with autism would be interested in driving, school or the other gender,’’ said Dr. Gary Gaffney, an associate professor of psychiatry at the University of Iowa College of Medicine. “Now we see they’re interested in all of the above. Now kids with Asperger’s syndrome are driving all the time, and we don’t really know the risks.”

A study led by Daniel J. Cox of the University of Virginia found high levels of concern among parents of teenagers who were on the autism spectrum. They cited worries about their children’s ability to concentrate, understand nonverbal communication and tolerate the unexpected. And while some techniques, like using a manual transmission, have been shown to be helpful in engaging teenagers with attention problems, they are not a good fit for people with Asperger’s, who often have trouble multitasking.

Kathleen Ryan, an instructor at Driving MBA, a school in Scottsdale, Ariz., said that keeping an open mind was important. “If you don’t go in thinking about their limits but think about their opportunity, they will never cease to surprise you,’’ she said.

Instructors of teenagers with Asperger’s tend to slow down the pace of instruction, breaking down tasks so they can be worked on one at a time. Ms. Ryan also includes time for role-playing situations that might fluster the student, like being pulled over by a police officer.

On the other hand, people working with teenagers with Asperger’s worry less about impulsive behavior. “It’s good that they’re more apt to follow the rules of the road,’’ said Dr. Patty Huang of the Children’s Hospital of Philadelphia. “They’re less likely to be reckless.”

Do you have a question about driving with Asperger’s? Ask the experts on the Consults blog.