The Monrovia, Calif., city council has approved the testing program for an emergency vehicle warning system developed with the help of the National Aeronautics and Space Administration's Jet Propulsion Laboratory in Pasadena.

The Emergency Vehicle Intersection Early Warning System, developed by E-Views Inc., will alert drivers to approaching emergency vehicles to reduce the potential for traffic collisions. The E-Views system involves the installation of transponders in several fire and police emergency vehicles and the installation of display boards on traffic-signal mast arms above the centers of intersections.

The transponders will communicate via microwaves with receivers on the display boards. As an emergency vehicle approaches the intersection, the firefighter or police officer activates the transponder, which turns the light to yellow, then red, for cross traffic.

The intersections' visual warning display signs also will be activated, and approaching drivers will see bright, flashing vehicle warning symbols on the displays. Those symbols will alert the drivers to the direction from which the emergency traffic is approaching, from as far away as 3,500 feet. The lighted icons will appear to move across the displays, synchronized with the actual emergency vehicle's movement.