The NSW Government has announced a one-year trial – to begin in September – which will require drivers to slow down to 40km/h when they are passing emergency service vehicles with flashing lights.

The limit will apply on all roads when police, ambulance, fire, SES or rescue vehicles are stopped and have their red or blue lights flashing.

"These new measures will help ensure the safety of our dedicated emergency service personnel," NSW Police and Emergency Services Minister Troy Grant said in a statement.

Jon Gregory, from the Riverina region of the State Emergency Service, welcomed the move to make emergency scenes safer.

He said SES personnel shared stories with him about passing motorists in the region who did not slow down when they were approaching emergency scenes, even though red and blue lights were flashing.

“I’d welcome anything that provides a safer working environment,” Mr Gregory said.

It is a view shared by Riverina Rural Fire Service operational officer Bradley Stewart.

Mr Stewart said RFS volunteers were recently called to a bushfire at Borambola, and had to ask for police assistance in slowing down traffic on the Sturt Highway.

“There were volunteers on the side of the road, fighting the fire, and there was a lot of smoke, but cars were still driving through the area at speed,” he said.

“This is a brilliant idea.”

Mr Stewart also cited the example of two NSW police officers were injured while setting up a random breath testing checkpoint in Sydney's southwest in February.

Senior Constable Jonathan Wright had to have his foot and part of his leg amputated and Senior Constable Matthew Foley broke his leg after a car ploughed into them.