A council in the south-west of WA could become the first in the state to ban cyclists from a road because of new rules that require motorists to give riders a 1-metre buffer when overtaking.

The laws are designed to keep cyclists safe, but there has been criticism regional roads are not wide enough for the 1-metre rule, forcing trucks and road trains off the bitumen and onto gravel as they overtake riders.

The laws are part of a two-year trial by WA Government, which require motorists to give cyclists 1 metre when overtaking at 60kph or less and 1.5 metres if the motorist is exceeding 60kph.

The Dardanup Shire Council is proposing to stop cyclists from using a narrow section of Harris Road, a busy one-lane road used by trucks.

Dardanup Shire president Mick Bennett said the overtaking laws did not work on regional roads.

"On some of our roads we're lucky to have 1.5 metres of tarmac, so it's just a recipe for disaster in some instances," he said.

"This one is purely and simply there's too much traffic on this road."

Dardanup Shire president Mick Bennett believes Harris Road is too narrow to allow trucks to safely pass cyclists. ( ABC South West WA: Gian De Poloni )

WA Police Minister Michelle Roberts said she was concerned by the proposal.

"Bicycles and trucks and other vehicles have shared roads in this state for decades without an issue, and it's always been a requirement that there be a safe passing distance if you're passing a cyclist," she said.

Shire has legal right to ban cyclists

The council has already approached Main Roads about the legality of closing the road to cyclists.

In a statement Main Roads said a local government did have the authority to close a road to vehicles of any class, including cyclists if it deemed it necessary.

John Hanczakowski, from the South West Cycle Club, said members had been riding on Harris Road for more than 20 years without an incident.

"It's generally quieter than other roads and traffic isn't a problem," he said.

Drivers who use Harris Road say it is not wide enough to safely pass cyclists. ( ABC South West: Kate Stephens )

The region's truck drivers believe the road is too narrow to accommodate the new overtaking laws.

Southwest Express Transport chief executive Mark Mazza said trucks would be forced to cross double white lines to overtake cyclists on Harris Road.

"That effectively pushes oncoming traffic off the road, so it puts more than just the pushbike rider at risk, it puts the truck driver themselves and oncoming traffic at risk as well."

Ban difficult to enforce

The proposal is open for public comment, but if it does go ahead the council is aware it would be difficult to enforce.

Cr Bennett said the council would not have rangers policing the road.

"We're trying to be sensible and practical about the fact that if you go out there you're taking a risk, so we're trying to take that risk out of it," he said.