Glasmann said the system uses GPS technology to permit authorized parties to know where the bus is located at all times.

"It gives a detailed road history. Any time the bus stops at any location, it records the date, time, and how long the stop lasted," Glasmann said. "Idle time is recorded, which helps save fuel. Is your driver sitting in a donut shop idling?"

The "geofence" feature allows administrators to demarcate bus routes by alerting administrators when a route's path has been violated.
—Robert Brumfield, "Do You Know Where Your Buses Are?," eSchool News, November 14, 2005

The technology causing a stir is called "geofences," and here`s how it might work:

A struggling salesman veers off his route and slinks into a bar. Within moments, his boss knows he`s there.

The bartender didn`t rat him out. It was his work-issued cell phone. By bringing it inside, the phone crossed a computer-generated "fence" drawn around the bar by the boss. A tracking chip in the phone triggered an e-mail that was sent back to the office: The salesman`s drinking at lunch again.

The geofences software is one of the latest trends in the work world. Depending on whom you ask, the technology is a productivity booster or an Orwellian threat, but one result is this: Your cell phone can now drop a dime on you if you`re goofing off.
—Shamus Toomey, "Bosses Use Cell Phones to Bust Errant Workers," Chicago Sun-Times, November 27, 2005

This means a car rental company can set up what Simmonds calls a "geo-fence." A car rented in Canada by a customer who intends to stay in Canada can be located or shut off if it goes into a hot zone by crossing the border into the U.S. or moving into a loading area at a port where it might be shipped out of the country.
—Johanna Powell, "New technology can pinpoint car's location," The Financial Post, February 14, 1997