FRIDAY, Sept. 6 (HealthDay News) -- Sleep-deprived teens are at increased risk of getting hit by a vehicle while crossing the street, researchers warn.

The new study included 55 teens, aged 14 and 15, whose ability to cross a street safely was tested in a virtual-reality setting in the Youth Safety Lab at the University of Alabama at Birmingham.

Teens whose sleep was restricted to four hours the night before the test took more time to begin crossing a street, crossed with less time before contact with vehicles and had more close calls than those who slept for eight and a half hours. Four hours of sleep is half the amount considered adequate for 14- and 15-year-olds.

The sleep-deprived teens averaged 2.2 close calls or hits by vehicles on 25 of the simulated street crossings, compared with 1.42 close calls or hits for those who had an adequate amount of sleep, according to the study, which was published Sept. 3 in the Journal of Adolescent Health.

The findings suggest that teens' ability to cross the street safely can be compromised after only one night of too little sleep, said study author Aaron Davis, a psychology post-doctoral fellow in the Leadership Education in Adolescent Health program at the university.

"It is easy to discount the idea that this loss of sleep could have a significant impact if it occurs rarely, but this study demonstrates that adolescents' safety could be put at risk after just one night of inadequate sleep," Davis said in a university news release.

An estimated 8,000 teens aged 14 and 15 require medical attention for pedestrian-related injuries each year in the United States, according to background information in the news release.

Study co-author David Schwebel, director of the Youth Safety Lab, said the study "demonstrates the importance of sleep for human functioning. Our results show clearly that insufficient sleep influences adolescent safety; without sufficient sleep, they are inattentive, distractible and poor decision-makers."

More information

The American College of Emergency Physicians has more about pedestrian safety.