Cellular phones have become one of the ways rental companies can provide a sense of security for business travelers.
For example, Hertz Corp. recently announced free emergency service in its cars with in-place cellular phones.
Following well-publicized violence against renters last year, the industry began to take a variety of steps to increase safety. Most have stripped car rental fleets of logos, signs and markers.
Even the bar-coded inventory control tags that used to be on bumpers or in rear windows have gone into hiding.
The industry is looking at ways to use cellular and related technology to add safety inside the car.
Avis Inc. is testing a system on 60 cars in New York using cellular phones that link the driver to a service center, which provides help ranging from traffic conditions to directions to emergency roadside aid.
About half those cars have satellite-assisted positioning devices, which allow the center and police to locate a car in distress. None of the cars have needed those services in a crime situation, Avis said.