There has been an increase in the number of roundabouts in Perth suburbs. The change is part of a broader effort to improve safety, reduce congestion, and modernise Western Australia’s road network, according to Main Roads WA and the WA Road Safety Commission.

According to the authorities, roundabouts are increasingly being chosen over traffic lights or traditional intersections because they reduce the severity of crashes. Their curved design forces vehicles to slow down, giving drivers more time to react and decreasing the risk of high-impact collisions.

A roundabout being used for vehicles in the suburb of Gosnells at an intersection. Photo: Angel Garavillas.

WA Centre for Road Safety Research director Teresa Senserrick said: “Roundabouts prevent these side impacts (also called T-bone crashes), with sideswipe (side-to-side) crashes much less likely to result in serious injury.”

According to the WA Road Safety Commission, about 19% of crashes with people killed-or-seriously-injured involved right-angled side impacts, which typically occur when vehicles collide perpendicularly at intersections.

In 2024, right-angle side-impact crashes again ranked among the leading causes of serious injuries statewide.

RAC WA, under their Risky Roads initiative, found that intersections are some of the most frequently nominated danger zones by local drivers.

Roundabouts are seen as one of the simplest engineering solutions to reduce these risks. In addition, the choice to install a roundabout, instead of traffic lights, depends on several factors, including traffic volume, speed limits, and nearby land use.

According to Main Roads WA, roundabouts are particularly effective in suburban areas where traffic volumes are moderate, and where slowing vehicles can improve safety for pedestrians and cyclists.

While the exact number of roundabouts in Perth has not been formally published, new developments and suburban upgrades feature them as standard design elements.

Local councils, working with Main Roads WA, often prioritise roundabouts for their proven record in reducing serious crashes. These can be planned in new estates and road upgrades because of their proven safety benefits and long-term cost efficiency.

In newer suburbs such as Harrisdale, Piara Waters, and Baldivis, roundabouts are now common at almost every major intersection.

However, the transition to more roundabouts hasn’t been without challenges. Multi-lane roundabouts can confuse some drivers, and vulnerable road users, such as cyclists and motorcyclists, may still face risks.

Insurance Institute for Highway Safety director of media relations Joseph Young said: “There may be an initial bump in less-severe crashes as drivers get used to the new design. Over time, crash rates decline.”

Perth driver Lance D’Cruz said he’s noticed the change firsthand: “I think roundabouts are convenient ways to facilitate intersections. But there are times when they can be frustrating. I’ve been stuck there for five or six minutes.”

The WA Road Safety Commission emphasised the importance of consistent design standards and public awareness campaigns to help drivers navigate these intersections confidently.