Ambulances in Stockholm will soon be piloting a system that interrupts whatever drivers are listening to – be it CDs, Bluetooth or the radio – and broadcasts a voice warning that an emergency vehicle is approaching.

Developed by students at KTH Royal Institute of Technology in Stockholm, the solution involves a radio transmission from the emergency vehicle to nearby FM tuners that are equipped with Radio Data System (RDS).

The signal is sent over the FM band along with the transmission of a text message that appears in the tuner display, said Florian Curinga, one of three students at KTH who developed the solution – called EVAM System – and founded a startup, H&E Solutions, to take it to market.

Crashes involving motorists who didn’t hear sirens are becoming more common as a result of improvements in sound insulation, Curinga said.

“Often drivers have only a few seconds to react and give way to emergency vehicles,” says Curinga’s partner, Mikael Erneberg, who also studies industrial engineering at KTH. “The optimal warning time is at least 10 to 15 seconds.”

Stockholm will begin testing the system in a limited number of emergency vehicles beginning in Q1 2017. “We want to catch motorists’ attention at an early stage, and mitigate stress that impairs road safety,” Erneberg said.

As long as the tuner is turned on, a voice message will broadcast on the system. Unlike lights and sirens, the warning system anticipates how far in advance messages need to be heard depending on the speed of local traffic. On a highway, for example, the signal will broadcast earlier than in slow city traffic.

Curinga said that the EVAM System would reach two-thirds of all vehicles on the road, and it could also warn of incidents along the route.

“It fulfills three functions: improving accessibility for first responders, improving road safety and make the working environment in transport better for vulnerable professions,” he said.