The world's roads aren't ready for a hotter climate

A man struggles to cross a road after his slippers got stuck in melted tar on a hot day in Ahmedabad, India, on May 20, 2022. PHOTO: REUTERS

LONDON (BLOOMBERG) - The historic heatwave that has smothered Western Europe this summer has caused transportation chaos.

Railroad tracks warped, airport runways failed, and key roads buckled.

On July 18, the busy A14 highway in Cambridge, England, was shut down after developing a bizarre ridge that, while enticing to skateboarders, would be calamitous to fast-moving cars and their passengers.

As it happens, the same thing has been occurring across America, Australia, China and Africa.

With average temperatures rising and heatwaves become more frequent and intense, infrastructure and, in particular, roads are increasingly vulnerable to human-induced global warming.

A 2017 study assessing the impacts of the climate crisis on critical infrastructure found that by 2080, heatwaves would account for about 92 per cent of total hazard damage in Europe's transport sector alone, in large part because the roads were built for cooler times.

Another study looked at data from weather stations used to determine the proper composition of local roads.

It estimated that around 35 per cent of them used materials unsuited to the actual climate.

"The maximum temperatures that civil engineers have been using in design are now being surpassed much more frequently," said Mr Amit Bhasin, a director at the University of Texas Centre for Transport Research.

"That's when the design starts falling apart."

Supply chains depend on vehicles with wheels to get goods, people and pretty much everything else everywhere.

Ships, trains and planes may do much of the long hauling, but those new jeans you ordered online will arrive at your door by van.

As roads fail more often, it is becoming clear how the economic cost of inaction could quickly add up.

The good news, though, is that the technology exists to sufficiently harden what is arguably the most critical of infrastructure.

The bad news is it will require governments at all levels to spend a lot of money upfront.

A SNCF employee checks the temperature of railway tracks in Bordeaux, France, on June 15, 2022, as a heatwave hits France. PHOTO: AFP

Most, if not all, the ways global warming has changed the climate are having a deleterious effect on roads everywhere.

Besides extreme heat, heavier rainfall and flooding triggered by the phenomenon can quickly erode highways and paved roads while obliterating those made of gravel and dirt.

The cost of repair can be steep: The devastating floods in Australia between 2010 and 2014 cost the government an estimated $6.4 billion in repairs to the road network.

In traditionally colder places, the problem is thawing.

According to a report from the Canadian Climate Institute, more than half of the country's winter roads in its northern regions, built on frozen lakes and rivers each fall, may in 30 years become unusable or impossible to build.

Nearly all could be gone by 2080, cutting off whole regions from critical services.

In Yukon, the cost to all-season roads largely made from gravel could total US$1.6 billion (S$2.2 billion) over the next two decades due to permafrost degradation.

And a paper published in 2020 warned that those responsible for building and maintaining roads in permafrost areas in China face "significant engineering challenges."

Huge cracks are already appearing in the roads, making them unusable.

According to Mr Claude Van Rooten, former president of the World Road Association, this summer's European heatwave is the latest reminder of the growing discrepancy between the planet's climate reality and what existing roadways can withstand.

He said that in order to weatherproof roads for a fast-warming future, government officials everywhere have to substantially rethink the way they are engineered.

"You try to make assumptions about what is going to happen, and climate change is changing those assumptions," Mr Van Rooten said.

If sufficient steps to mitigate against temperature and precipitation changes are not taken, the bill for repairing and maintaining roads worldwide will skyrocket.

Across Africa alone, the tab could reach US$183.6 billion by 2100, according to University of Colorado research.

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