Most of the cars are well insulated against traffic noise. Sometimes it’s difficult to hear appearance of an ambulance with a siren, especially with the loud music blasting in your car. Students from Sweden’s KTH Royal Institute of Technology have developed a system in which drivers’ stereos alert the presence of approaching emergency vehicle.
The signal is sent over the FM band along with the transmission of a text message that appears in the tuner display. This will cause the current audio playback to be interrupted – be it from radio, CD, Bluetooth, USB or any other source – with a voice announcement that an emergency vehicle is approaching. The system is called EVAM System, and anticipates how far in advance messages need to be heard depending on the speed of local traffic. On a highway, the signal will broadcast earlier than in slow city traffic. The optimal warning time is at least 10 to 15 seconds.
It is estimated that the EVAM System should be able to alert approximately two thirds of the cars on Swedish roads. The team of students founded a startup, H&E Solutions, to take EVAM system to the market.