Cool Roads program

The City of Perth is trialing a heat-reflective coating to help keep road surfaces cooler.

The trial, which will start with 2.5km of sections of roads in East Perth and Crawley, is part of the City’s efforts to better understand and manage the urban heat island effect.

This is the first time the City has trialed the reflective pavement treatment on its road network.

The coating has been used in car parks and on some roads in regional Western Australia and similar treatments have been tested in other Australian states and internationally, including in the United States.

Traditional dark asphalt absorbs significant solar heat.

The Cool Roads treatment sees a lighter-coloured reflective coating applied to the road surface, which increases the surface’s reflectivity (which is called albedo), meaning more solar energy is reflected away from the surface rather than absorbed into the pavement.

Trials have shown that reflective pavement coatings can reduce road surface temperatures between 3 and 11°C in warm conditions.

In some cases, this can also contribute to small reductions in surrounding ambient temperatures of around 1-2°C, improving pedestrian comfort.

No.

Reflective pavements reduce the amount of heat absorbed and stored in the road surface.

This helps limit heat that would otherwise be released back into the environment later, which contributes to the urban heat island effect.

Roads and paved surfaces make up a large portion of Perth’s built environment and contribute to heat build-up.

This trial will help the City understand how reflective pavement technology performs in Perth’s climate, including temperature impacts, durability and maintenance requirements.

Yes.

In addition to potential cooling benefits, the coating can help extend the life of existing asphalt by slowing the ageing of pavement materials.

This may reduce the frequency of resurfacing works, saving costs and minimising disruption and construction impacts over time.

This trial covers approximately 2.5 km of roads throughout East Perth and Crawley and will be monitored over time under real traffic and weather conditions.

The coating typically has an expected lifespan of around nine years, depending on traffic volumes and environmental exposure.

Reflective pavement coatings are generally suited to low to moderate speed urban roads, typically those with speed limits of 60 km/h or lower.

Reflective pavements are just one of the ways the City is tackling urban cooling. Other initiatives include:

• Expanding tree canopy and urban greening
• Increasing shade through urban design choices
• Using cooler construction materials
• Supporting water-sensitive urban design.

The City is also protecting existing trees through projects like the Perth Convention Centre Car Park Rehabilitation, which used tree-sensitive engineering to retain mature trees and preserve canopy coverage.