The Greyhound bus company is installing a satellite based security system that provides additional GPS functionality and two way voice communication via cellular ground services.

Dubbed the On-Guard Tracker System by manufacturer ATX Technologies, the system will be installed on 250 buses following testing on 10 in service Greyhound coaches. The system allows drivers to contact an emergency center or a Greyhound dispatcher at the push of a button.

On-Guard Tracker combines a global positioning system with wireless technology that allows two-way communication and tracking. The initial 250 units will be operational before the summer travel season. If the test is successful, Greyhound expects to install the system on all 2,400 buses in its network.

"After several years of study, this is the first comprehensive system we have been able to find that provides the coverage we need," said Greyhound CEO Craig Lentzsch, adding that Greyhound would be the first intercity bus company with such a capability.

The On-Guard system, manufactured by ATX Technologies, Inc. of San Antonio, consists of a telephone handset and two buttons easily accessible from the driver compartment. Drivers may press one button to reach the On-Guard Response Center, where trained technicians assess the situation and coordinate a response from police, fire or emergency medical personnel.

ATX Response Center emergency communications specialists can also track the location of a bus when the driver is unable to communicate verbally.

Drivers can press a second button to reach Greyhound's operations support center for non-emergency communications. Additionally On-Guard can allow operation centers to notify drivers of route changes and traffic conditions.

Greyhound is the only nationwide provider of intercity bus transportation, serving more than 2,600 destinations with 18,000 daily departures.