What GPS vehicle tracking is and how it actually works

The device in the vehicle picks up the signal from GPS satellites and uses it to calculate its own position. Along with the position it records the time, speed, direction and whether the ignition is on.

That record is sent over the mobile network to a server, where it is assembled into a route and shown on a map. When there is no mobile signal (a tunnel, an underground car park, a hill with no coverage) the device stores the records and sends them as soon as the network is back, so no gap is left in the history.

Position, time, speed, direction and ignition status, and derived from those: trips, stops, distance covered, and entries into and exits from zones you draw yourself.

On compatible vehicles, data from the vehicle's own bus is read as well: fuel level, engine hours, revs. That is a separate package and it depends on the vehicle model, so it is confirmed by a technical check.

The device does not record audio, does not record video and does not access phones in the vehicle. It does not read messages, does not track private devices and does not know who is behind the wheel; it knows the vehicle it is fitted in.

That is worth knowing for the conversation with drivers, too: much of the resistance comes from an assumption that the cab is being listened to. Once you spell out exactly what the device records, the subject usually closes.

On the open road the position is accurate to within a few metres. Between tall buildings, inside halls and under flyovers the signal bounces, so the point can drift into the next street.

That is why the position is read together with the route and the time, and not as proof that the vehicle stood on that particular pavement. For disputes about whether and when a vehicle was at an address, that is perfectly enough; for measuring to the metre, it is not.

It does not plan routes in place of the dispatcher, it does not establish fault in an accident and it does not replace a conversation with the driver. It gives you a clean record of what happened; what you do with that record is still a human decision.

Companies that expect tracking to improve discipline on its own are usually disappointed. The ones that use it as a shared record, which both the dispatcher and the driver can refer to, get a great deal more out of it.

Tracking company vehicles means processing employee data. Before the first trip drivers must be informed, in writing, and the purpose of the tracking should be clearly defined and limited.

We have split the legal side into a separate guide, and when you come on board you get a ready-made notice template for employees. That is the one part of the job no provider can do for you.