The city of Charleston has installed global positioning system (GPS) technology on its garbage trucks to improve route efficiency. The satellites and computer provide not only real-time data, but also allows the city to more efficiently plan trash routes. Now trash collectors finish routes more quickly, saving the taxpayers overtime and saving motorists time that might otherwise be spent sitting behind a slow-moving truck on a narrow street. Charleston already had GPS systems on its emergency vehicles. It cost $9,000 total to install GPS units on 18 city garbage trucks. The GPS service costs an additional $450 per month. The system allows a dispatcher sitting at a computer to know the location of a city garbage truck at any time. If a truck has been slowed because of a heavy trash load, other trucks can be dispatched to help finish up the route, said Mike Metzler, deputy director of operations for the city's Department of Public Service. The dispatcher also knows if there are delays at the landfill, if a truck breaks down, or if a truck is delayed in a traffic jam.