Though the majority of young people with high-functioning autism choose not to get behind the wheel, new research suggests that a substantial number seek the independence that driving offers.

In the first large study to look at driver’s licensing rates among those with autism, researchers found that about a third of those on the spectrum with no intellectual disability received a license by age 21.

The study published this month in the journal Autism cross-referenced health records for over 52,000 kids born between 1987 and 1995 who lived in New Jersey with information from the state’s driver licensing records.

“We know that driving can increase mobility and independence for adolescents with ASD, but little was known about their rates of licensure,” said Allison E. Curry of the Children’s Hospital of Philadelphia who worked on the study. “Our results indicate that a substantial proportion of adolescents with ASD do get licensed, and support is needed to help families make the decision whether or not to drive before these adolescents become eligible for a learner’s permit.”

Nearly all of those who obtained a learner’s permit went on to get a license, the study found.

However, adolescents with autism who sought a driver’s license took longer to do so than their typically-developing peers. Individuals with the developmental disorder obtained an intermediate license — allowing for independent car travel during daytime and evening hours with limited passengers — roughly 9.2 months later.

Researchers recommended that parents of teens with autism who are considering driving discuss concerns about attention span and other possible barriers with a doctor. What’s more, they said that an occupational therapist who focuses on driving skills or a driving instructor with experience training those with special needs can be helpful.

“For teens on the autism spectrum, the decision to pursue a driver’s license is one of several milestones that other families might take for granted,” said Benjamin Yerys, a scientist at Children’s Hospital of Philadelphia and co-author of the study. “ASD can affect decision-making, information processing and attention to varying degrees, and we need to understand what resources, specialized instruction, and other supports might be helpful for teens and adults with ASD who are considering or preparing to drive.”