I was on a bike ride this weekend. I was sitting at an intersection waiting for the light to turn green. As I was waiting, a big fire truck turned into the road to my left and started heading toward the intersection with its siren wailing and all the lights flashing.
As the fire truck approached it got louder and louder. It became so loud that I reached up to hold my ears. The amount of noise coming out of the siren was deafening. The light turned green, and everyone in my lane sat there waiting for the firetruck to go through the intersection.
However, in the lane facing us, there were cars that had completely missed the firetruck's light show and siren. When the traffic light turned green, one car shot right into the intersection without a care in the world and nearly ran into the fire truck.
This is amazing if you think about it, because by this point I could nearly feel the pressure waves of sound coming from that siren. I have no idea what the decibel rating of a modern siren is, but it must be huge. Which makes sense, given that the sound of the siren has to penetrate the cabin of modern, sound-proof automobiles and overpower the sound of unmuffled Harleys.
But the fact that I was having to hold my ears to avoid deafness, while cars were moving into the intesection oblivious to the siren's sound, shows that we have reached the end of siren technology. It is time to think of a better solution. Sirens cannot get any lounder without causing local earthquakes. Sound waves simply are not the answer.
In 20 years, when robots are doing all the driving, this will be a moot point. Emergency vehicles will send wireless messages to robot drivers telling them to move out of the way seamlessly. The interesting question is, what do we do in the meantime to create an inexpensive, better solution to the problem that sirens are trying to solve?