Even children who look both ways before crossing a street run the risk of being struck by a motor vehicle when sleepy, according to a recent study conducted at Children’s of Alabama.

The study utilized a virtual reality pedestrian environment and found that children with untreated excessive daytime sleepiness were twice as likely to be struck or nearly hit by a vehicle. Although sleepy children looked appropriately at oncoming traffic, they exhibited impaired decision making when attempting to cross the street.

The study was coauthored by Dr Kristin Avis, associate director of the Sleep Disorders Center at Children’s and associate professor of pediatrics at the University of Alabama at Birmingham (UAB), Karen Gamble, assistant professor of psychiatry at UAB, and David Schwebel, professor of psychology at UAB, and appears in the February issue of SLEEP.

“In our study, sleepy children were much more likely to become a victim of a pedestrian accident involving a motor vehicle,” Avis says in a release. “Basically, they were going through the motions of looking left to right, but not processing the world around them or making safe decisions on when to cross a street.”

The study introduced a virtual reality pedestrian environment to 66 children between the ages of 6 and 18—half of whom were being treated for narcolepsy or excessive daytime sleepiness (EDS). The other half was comprised of healthy children. The results concluded that children with EDS were riskier pedestrians than the healthy children and twice as likely to be struck by a virtual vehicle in the environment as the healthy children of the same age, race, and gender.

Pediatric pedestrian accidents have increased significantly at Children’s of Alabama within the last 5 years. In 2013, Children’s treated 41 trauma patients in relation to a pedestrian accident, up from 30 in 2009. In just the first 2 months of 2014, Children’s has recorded six traumas involving pedestrians and motor vehicles. Annually, 5,300 American pedestrians are killed and 85,000 others are injured, according to the National Center for Injury Prevention and Control (NCIPC). In middle childhood, 60% of pedestrian injuries and deaths occur when the child is crossing the road at or between intersections, typically within a half-mile of the child’s home.