Global Positioning Systems (GPS) use a network of satellites beaming time-stamped signals to receivers on the surface of the Earth. By measuring the delay between when the signal was sent and when it arrived from three different satellites, you can isolate the coordinates of any receiver on the surface of the earth, with a precision that goes down to inches for military receivers, and about two years for commonly available civilian gear.

GPS equipment has become more and more common as cell phone technology has made it more portable and easier to use. There are many benefits to equip your fleets with GPS tracking technology.

Firstly, GPS equipment, and the monitoring software for it, allows you to have precise locations of delivery vehicles. This makes it possible to route technicians and repairmen and delivery personnel more efficiently, and to let customers know, nearly in real time, about any potential delays in routing or delivery.

Second, because of more accurate data gathered on the movements of vehicles in your fleet, you have better control over mileage, proactive maintenance, and fuel economy. It's a lot easier to keep track of fuel economy when you can factor in idle times.

In similar vein, you now have an accurate record of where every vehicle in your fleet has traveled over the course of a given day. Your payroll expenses will go down; when you have an accurate log of where every vehicle is at every hour of the day, you can cross reference it against employee time sheets for hours spent driving for reimbursement.

Likewise, most vehicle-tracking GPS software allows you to set a "virtual fence" which lets you tell when a vehicle has gone "out of zone" - this is good for tracking if a vehicle has made an unscheduled detour, or to track it down if it's stolen.

Finally, more and more GPS tracking software can work with a public web interface. It can be a great marketing coup for a taxicab company to have a web site that shows, as an overlay on Google maps, the location of all cabs reporting in, whether they have a fare and so on - this makes it much easier to schedule a cab pickup, or run a bus route with accurate time stamps for how far ahead or behind a bus is on its scheduled rounds.

All of these make GPS tracking gear for your fleet's vehicles a worthwhile investment; it's estimated that the more accurate timekeeping versus payroll expenses can cause a typical small business with a fleet of company vehicles to save enough money to pay for the installation and software in under 90 days.