Sam Trans is going to install GPS’s so riders can track buses. People waiting for a bus in San Mateo County will soon be able use their cellphones to find out exactly when their bus will arrive.

The San Mateo County Transit District, which operates SamTrans buses, is spending $1.2 million to have a global positioning system trackers installed on its buses. The GPS system will track the location of a bus as it proceeds along its route.

Passengers who ride the district’s buses will be able to use their cellphones or the Internet to check the arrival and departure time of buses.

A SamTrans spokeswoman says the GPS project is expected to be completed by March 2010.