I was watching the ABC's "New Inventors" program today and saw an invention by a FF from the MFB. He's made a radio transmitter that can be installed on trucks, and broadcasts a recorded message on all FM and AM channels. Basically, it sounds a warning signal then says "Give way to approaching emergency vehicle" (or similar).
It reaches about 300M in front of the truck, a little less to the sides, and nothing at the back, so cars with their radios on in front of the truck, and to the sides (like at intersections) will hear the warning, probably well before they hear the siren.
I see it as a great invention maybe not as usefull in country areas, but its a great idea... what do other people think?