A trial of speed bumps on shared bike and pedestrian paths will be launched shortly in high-traffic areas in Perth, in a bid to get bicyclists to slow down.

Department of Transport acting executive director Craig Wooldridge said as cycling had risen in popularity the department had seen a lot more conflict between walkers and riders.

Mr Wooldridge said the department had tried to get riders to slow down with "slow points" and surface treatments such as those deployed at City West train station, but with limited success.

The height and spacing of the speed bumps still need to be refined, but the department expected to roll out the trial at Claremont and Bayswater train stations, and the bike path along the river in Alfred Cove in the not-too-distant-future.

The features will have warning lights at night and will be clearly signed.

First test bumps too steep

The speed bump was trialled on a cycling path in Leeming. ( ABC News: Damian Smith )

The WA Department of Transport initially tested out the speed bumps at a park in Leeming, in southern Perth, but found they were too close together and too steep.

"Kids on their scooters were bottoming out on the humps, and the hand cyclists, they were bottoming out as well," Mr Woolridge said.

"One of my staff was towing his kid in the back of one of those kids' trailers, he had a bit of instability in the back there.

"The kid loved the ride and wanted to go again, but not really what we want out on the path there."

The bumps will also be tested by people in wheelchairs, mobility scooters and people with vision impairments.

He said the areas targeted for the live trial had been subject to complaints.

Westcycle chief executive Matt Fulton welcomed the idea as a short-term solution to congestion problems on paths.

"We constantly tell the cycling community that we expect to give pedestrians the same respect that want motorists to give us," he said.

"It's a good idea that we all slow down and ride to the conditions."

But he said Australia should ultimately be aiming separate paths for pedestrians and cyclists in areas of high traffic.