Ambulances in Stockholm are testing a system that interrupts in-car audio systems to warn drivers that they need to get through. The solution was developed by students at the KTH Royal Institute of Technology. It broadcasts a voice warning, while a text message also appears in the radio display. It uses an FM radio signal to jam drivers' speakers and stop music playing according to BBC News. It will be able to alert cars with their FM radios turned on and also interrupts Bluetooth connections.
The radio transmission is sent from the emergency vehicle to nearby FM tuners that are equipped with RDS, a communications protocol for embedding small amounts of digital information in FM radio broadcasts. It is most commonly used to display the station or song title.
Often drivers have only a few seconds to react and give way to emergency vehicles, said Mikael Erneberg, a KTH student who worked on the system.
Loud music can prevent sirens from being heard and, according to the students, accidents involving motorists who have not heard emergency vehicles are on the rise. It fulfils three functions: improving accessibility for first responders, improving road safety and make the working environment in transport better for vulnerable professions, said Mr Erneberg.
The city will begin testing the system in a limited number of ambulances and fire engines, with plans to expand across the country later this year.
Read the BBC News story
In 2016 Sweden rejected a proposal for a transition of on-air broadcasting to DAB+ and will retain the FM network. One of the main reasons is safeguarding a robust and well-established radio system for complete safety and emergency national coverage.
