In Australia, Yarra Trams tests an innovative solution to combat the urban heat island effect

Context: Mitigating the dangers of high temperatures at Melbourne’s busiest tram stop  

Australia’s hot summer climate, with temperatures occasionally reaching 40 degrees Celsius (equivalent to 105 degrees Fahrenheit), poses a threat to people’s comfort and safety. Adding to the challenge is the urban heat island effect, caused by a dense concentration of streets, sidewalks, buildings and other hard surfaces that absorb and retain heat.

One of the hottest places is Federation Square, the busiest tram stop on the Yarra Trams network, operated by Keolis Downer.

The Passenger Service team at Yarra Trams sought an innovative solution to mitigate the heat and lower the temperatures felt by customer service teams and passengers. Their chosen approach involved applying a UV-repellent coating to asphalt surfaces. 

Innovation: Cool Seal, a UV-repellent road coating to reduce surface and ambient temperatures 

The local teams explored a promising American solution extensively used in Phoenix and Los Angeles: Cool Seal, a high-performance, water-based asphalt emulsion seal coat designed to achieve lower surface temperatures, thanks to its light color and UV-repellent properties. By reflecting sunlight rather than absorbing it, Cool Seal significantly lowers surface and ambient temperatures – unlike traditional asphalt, which exacerbates urban heat.  

Some municipalities in Adelaide, South Australia, had already tested Cool Seal on road surfaces, finding that it reduced surface heat by 8 degrees Celsius (45 degrees Fahrenheit). 

Benefits: Reduced temperatures for improved passenger/staff comfort and safety 

By using Cool Seal at the Federation Square stop, the Yarra Trams teams hoped to reduce temperatures felt at the stop. The ultimate goal was to promote a comfortable and healthy environment, enhance team member and passenger satisfaction, reduce the risk of heat stress by improving the work environment, and potentially extend the lifespan of the asphalt surfaces. 

Following installation before the summer season, the solution underwent testing with heat guns when the summer arrived to ensure its effectiveness. As a result, surface temperature readings were 4 to 5 degrees Celsius (39-45 degrees Fahrenheit) cooler in areas where Cool Seal had been applied, thereby reducing heat for passengers and team members. 

Furthermore, Cool Seal visibly brightened the Federation Square stop, reduced noise and improved the experience for tram drivers and workers.

Next steps: Testing the Cool Seal solution at other stops in the Yarra Trams network  

After the promising results from the initial trials, Yarra Trams plans to continue collecting feedback from teams and conduct additional heat readings to confirm the solution’s effectiveness.

Depending on these results, the solution may be expanded to other stops and different applications across the tram network, further mitigating the urban heat island effect and reducing air conditioning costs. For example, the solution is being tested on the platform (rather than the track) at Rod Laver Arena, another busy stop on the network.

In the meantime, Keolis’ innovation with Cool Seal has garnered interest from various businesses around Melbourne, with government offices and emergency services emerging as key partners.