GPS trackers not only help to monitor drivers and employees but to improve their security in case of emergencies.

Employee-tracking devices have gained steam thanks to ever-more-accurate GPS technology and a U.S. mandate requiring wireless companies to develop ways for emergency workers to find the physical location of people who dial 911 on a cell phone.
Employees and drivers not even have to call 911. Their dispatchers can monitor through the GPS tracking system if they have an emergency.
Developed in the 1970s by the U.S. military, GPS uses signals from low orbit satellites to triangulate the position of a ground-based receiver. GPS trackers were once an expensive luxury, but costs have plunged with the expansion of cellular-phone services.
Enhanced 911 (E911) emergency regulations governing wireless carriers unleashed profitable new GPS services, analysts say. To comply with the rules, carriers began running more accurate GPS technology capable of supporting a range of commercial services that go beyond emergency location.
SOURCE: news.cnet.com