Unsupervised children in vehicles: a risk for pediatric trauma. In this study, a series of instances of children injured by a motor vehicle set in motion by an unsupervised child are reviewed. During a 24-month period, nine such children were identified through a multihospital and coroner's office monitoring system in a single urban county. Injuries ranged from multiple abrasions and contusions to serious leg and head injuries. Three children died. The typical circumstance involved a child releasing the brake or placing the vehicle in gear in a private driveway which resulted in the vehicle striking or rolling over the victim. In four of the nine cases, the child who set the vehicle in motion fell or jumped from the vehicle and then became the injured victim. The extent of these unusual motor vehicle-related injuries is unknown because they are unlikely to be reported in official police statistics. According to the study findings, there is a need to educate the public and health professionals about the risks associated with leaving a child unattended in a motor vehicle and the hazardous environment of the private driveway. Preventive measures would include not leaving a child unattended in a vehicle, locking unattended vehicles to prevent access, and redesigning of private driveways. 