Watch Sam Blackledge's report
Ambulances and other emergency vehicles are regularly struggling to get through Exeter due to a controversial low traffic zone, it has been claimed.
The trial restrictions in Heavitree and Whipton were brought in to make the area safer and cut down on air pollution.
Protesters gathered outside County Hall on Thursday - and claimed the scheme is affecting the emergency services.
Campaigner Ian Frankum said: "Only this morning, the tenth emergency service vehicle was caught at the blocks. How long before it's going to be of a dire consequence?"
Mr Frankum accused Devon County Council of failing to properly consult residents.
"We're seeing more and more traffic on the arterial roads, more congestion, more pollution," he said.
"They're just pushing the traffic out onto those roads. So they need to really halt it. They need to speak with the residents, look for the right ideas. Everyone wants safer streets, everyone wants less pollution.
"The council is just ignoring all the pleas from the thousands of residents who are actually saying this is just simply not working."
A Devon County Council spokesman said: “Consultation is ongoing on our Active Streets pilot scheme which intends to reduce traffic volumes on residential streets in Heavitree and Whipton, making it safer for people to walk and cycle.”