More than 1.5 million vehicles crowd the roads and expressways that make up the Chicago district's patrol area. The district handles 20,000 crashes a year, and has developed a program to reduce the amount of time that officers spend processing mass traffic accidents. If an accident has not caused personal injuries, an individual can phone in a report instead of waiting for a trooper to arrive at the crash site. In addition, utility trucks from the Illinois Department of Transportation patrol the highways to help stranded motorists, freeing troopers for other assignments. One of the newest, most versatile and widely used services the Chicago district shares with its fellow agencies is Air One, a helicopter stationed at Midway Airport. The helicopter is available for manhunts, surveillance, gang suppression operations, searches and many other operations. The district's three squads work general criminal investigations, including approximately 60 homicide cases each year, and have started a special effort to take a fresh look at previously unsolved homicides.