<div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>It's that time of the year when crossing a bitumen road in </span><a href="https://www.9news.com.au/building" rel="" target="_blank" title="urban Australia"><span>urban Australia</span></a><span> feels like you're treading on melted goo.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Summer temperatures in the outer suburbs of Sydney, Melbourne and other capital cities regularly hit 40 degrees or more, but the impact of the heat goes far beyond making you feel sweaty and uncomfortable.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>About 30 per cent of roads are constructed from thick black asphalt, and can reach up to 75 degrees in summer months.</span></div></div><div><div id="adspot-mobile-medium"></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><strong><span>READ MORE:</span></strong><span> </span><a href="https://www.9news.com.au/world/earth-at-hottest-temperature-of-the-past-125-000-years/902f6b6f-dabf-4d5c-abb1-0e9b16e693d7" rel="" target="_blank" title="Earth at its hottest temperature in 125,000 years, report finds"><strong><span>Earth at its hottest temperature in 125,000 years, report finds</span></strong></a></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>They're part of a serious problem impacting not just the built environment, but people's health.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Deaths from </span><a href="https://www.9news.com.au/national/climate-change-research-people-in-cities-at-greater-risk-of-dying-in-heatwaves-news/75a2dbe8-b04c-4be0-87e6-78274cf68902" rel="" target="_blank" title="hot weather in Australia"><span>hot weather in Australia</span></a><span> outweigh natural disasters, such as cyclones, floods and bushfires.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>And the scorching conditions in cities have been made worse by rapid development creating so called urban heat islands on their outer ranges.</span></div></div><div><div class="OUTBRAIN" data-reactroot="" data-src="//www.9news.com.au/national/how-lighter-coloured-roads-can-cool-australian-baking-suburbs/cea9efeb-fa0a-442e-93fe-be94c749a666" data-widget-id="AR_5"></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>But what can be done to cool them down, and ensure the suburbs of the future don't become heat magnets? </span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Part of the answer to cooling them lays with an innovative method of keeping secret US spy planes undetected.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><strong><span>READ MORE:</span></strong><span> </span><a href="https://www.9news.com.au/national/air-conditioning-harming-health-in-hot-environments-study-finds/ca19c041-d895-4971-b66b-dda056720d8f" rel="" target="_blank" title="How adopting a 'siesta' culture could help Australians beat extreme heat"><strong><span>How adopting a 'siesta' culture could help Australians beat extreme heat</span></strong></a></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>It's been taken up by urban planners across the world, and is part of the "out of the box" thinking needed to stop Australia's big cities getting even hotter, one expert says.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Professor Sebastian Pfautsch, an urban heat expert at the University of Western Sydney, says the solution adopted by the Pentagon was CoolSeal, a white-coloured, asphalt-based sealant.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Painting it on runways ensured US reconnaissance aircraft parked on hot tarmac reduced radiating heat that could be detected by foreign military satellites.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>"There are lots of options in urban design when we want to mitigate those warming effects," Pfautsch said.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>CoolSeal was embraced by Los Angeles authorities when they launched an extensive program to reduce the surface temperature of the city's roads by about 1.6 degrees over 20 years.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>A months-long trial to discover if cooler roads could reduce the air temperatures was undertaken by three western Sydney councils in 2020.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>It saw 40,000 square metres of road painted with cooler colours - resulting in heat loss by up to 14 degrees on the surface.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>But because the surrounding infrastructure was dark, it meant there was no drop in air temperature - the crucial measurement for protecting people from severe heat.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>"In Los Angeles, they painted many square kilometres of suburbs with heat-cooling paint and the result has been the air temperature is much cooler," Pfautsch said.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>There are other urban design changes that can reduce suburban heat - such as banning black roofs that soak up the baking summer heat, a measure introduced in South Australia.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>But less politically contentious is moving away from asphalt-covered roads - suitable for highways and major arterial routes - but absorbers of intense heat in the suburbs.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Pfautsch says changing their design can also help foster community spirit in suburbs.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>"We could do better when it comes to residential roads," he said.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>He points to the concept of "play streets" that have been widely adopted in Europe.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>To balance demands of motorists and pedestrians, they have a speed limit of 15km/h or less.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Typically, the road surface is made of light-coloured permeable concrete, allowing the flow of water for cooling. </span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Wider verges can provide more green space and shading.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>At certain times, the streets are closed to traffic, enabling children to safely play on bikes and scooters and neighbours to congregate.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>"It's a great concept for residential streets ... much better than just bitumen."</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><a 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