Torrential rain destroyed a cliffside road in New York. Can U.S. roads handle increasingly extreme weather?

The Northeast section of the U.S. was hit with a deluge of severe storms on Sunday that caused deadly conditions on roads. Flooding was so severe that in upstate New York, a cliffside road completely shattered. 

CBS News correspondent Errol Barnett saw a massive chunk of Route 218 totally missing. 

"The rainfall here was so intense, the downpour was so torrential, that these drainage pipes couldn't handle it," he said. "It ripped away the dirt, the debris, the drainage pipes, the asphalt. ... It's one example of just how dangerous fast-moving storm systems can be in treacherous places like this." 

But this isn't the first time extreme weather has caused concrete to crumble. High temperatures are known to cause roads to buckle, which happened this summer in Texas when at least two different highways suffered damage from triple-digit temperatures. 

With all of this extreme weather, are roads across the U.S. able to withstand the even more extreme weather that will come if global temperatures continue to increase? 

The U.S. Environmental Protection Agency says that while the nation's transportation system "is built to withstand weather," that "climate change may affect this system over time." 

Here's what to know. 

How are U.S. roads made? 

The U.S. is the third-largest country in the world, taking up almost 4 million square miles of land. That means it requires a lot of space for roads – and that's exactly what it has. 

There were nearly 4 million miles of roads in the U.S. as of 2006, according to the U.S. Geological Survey, more than 45,000 of which are part of the Interstate Highway System. And the agency says that nearly all of the materials that are used to build these roads are being continuously used, except what's diminished from "maintenance" and "wear and tear." 

A typical U.S. highway has three layers, the agency says – compacted soil on the soil, roughly 21 inches of natural aggregates in the middle, and about 11 inches of concrete on top. That top layer is generally a combinate of different materials as well: about 60-75% aggregate, 15-20% water, 10-15% cement, and 5-8% entrained air. 

Dr. Klaus Hans Jacob, a geophysicist who has worked at Columbia University's Lamont-Doherty Earth Observatory for more than 50 years, specializes in disaster risk management related to climate change. He told CBS News that roads and highways typically have an embankment that they are built upon, which can cause a problem when they are built to cross or near streams and rivers. 

The real issue, however, is that the data that has been accumulated in decades past to build roads "reflect only the past weather and climate conditions and not the current and future climate conditions," he said. 

"Our roads and highways and settlements are not built to deal with these new flash floods that we are now facing," he said, or the other effects of climate change, such as extreme heat. 

More precipitation and sea level rise

Jacob told CBS News that a warmer atmosphere means a warmer ocean, which brings more moisture back into the air. When the increased precipitation and moisture cause bodies of water to swell, the force can "just take away the gravel, sand and aggregate rocks and pebbles" that go into building the roads.

"That moist, warm air drifts inland. Then it's capable of pouring cats and dogs kind of rainfalls onto the land and in amounts and rates that are not reflected by the past data," he said. "...They were not designed to deal with these kind of flash floods and so the embankments simply erode away. ... And when the bank underneath the road is undermined, then of course, it collapses." 

Sea level rise and more frequent and intense extreme storms, both of which are likely to hasten with climate change, can take a heavy toll on roads, with the EPA saying it can weaken road materials, as well as the other impacts Jacob mentioned. 

"As a result, people may have trouble getting to their homes, schools, stores, and medical appointments," the EPA says.

Even farther inland, where precipitation is expected to also increase, roads will likely see an impact as storms can bring flooding and mudslides. 

"Exposure to flooding and extreme snow events also shortens the life expectancy of highways and roads," the EPA says."... Road infrastructure in coastal areas is particularly sensitive to more frequent and permanent flooding from sea level rise and storm surges."

Extreme heat causes roads to buckle

Most roads in the U.S. are made of asphalt concrete, a material primarily made by adding asphalt cement to sand and rock, according to the U.S. Department of Transportation. The problem with this, however, is that when temperatures get too high, it can cause the pavement to "soften and expand," the EPA says. 

"Pavement expands and contracts as temperatures rise and fall," the Wisconsin Department of Transportation said in a 2019 video explaining the impact. "it is designed to accommodate these changes. But in extreme heat with excessive moisture content, the pavement expands beyond its design limits. This pushes the pavement up or breaks it apart."

Jacob explained that the asphalt "becomes putty" under extreme heat. 

"Essentially, instead of having a solid road, you have a pasty road and when cars and trucks drive forward, that paste gets displaced and deformed," he said. 

The heat has been causing this issue across the U.S. for years. Just two weeks ago, a segment of Interstate 10 in Texas buckled because of the high temperatures, the Texas Department of Transporation reported, closing down lanes of traffic as segments of the road crushed together to form a massive unstable barrier. 

Roads "unsafe" for emergencies 

In 2021, the U.S. Government Accountability Office issued a report saying point-blank the dangers that come with roads that aren't resilient to climate change. 

"If U.S. roads aren't built to withstand changes in the climate, they may be unsafe routes for emergency evacuations and expensive to fix after a disaster," the nonpartisan agency said. "Climate-related damages to paved roads may cost up to $20 billion annually by the end of the century." 

Jacob said that when it comes to precipitation-caused damage, it's hydrological dynamic effects that would be difficult to account for even if future weather was better predicted. 

"But with proper funding and engineering, you could solve those problems," he said. 

To prevent future issues, the government agency recommended 10 options for the Department of Transportation to adopt. This included integrating climate resilience into the Federal Highways Administration's policy, updating design standards and building codes and linking climate resilience actions to incentives or penalties. 

Jacob suggested using more cement-like materials could help make roads more durable, though he said that alternate materials are not his expertise. 

"Everything can be solved with proper funding, with proper design and proper environmental information and data to make those engineered infrastructures sustainable vis a vis the climate that we face," he said, adding that if changes aren't made, it could lead to economic losses "in the tens of billions" across the nation, if not more. 

The Federal Highway Administration said that it is continuing to implement a "coordinated approach to help states repair and rebuild roads and bridges that have been damaged by catastrophic events," including those related to weather. Recently, the department said, the Biden administration said it would provide $749 million in Emergency Relief Program funds to 39 states, the District of Columbia and Puerto Rico.

The department also cited the administration's goal of "rebuilding more resilient infrastructure." 

"Specifically, the Bipartisan Infrastructure Law addresses the future resiliency of transportation infrastructure in the face of climate change through new programs and expanded eligibilities, including the Promoting Resilient Operations for Transformative, Efficient, and Cost-saving Transportation (PROTECT) Formula and Discretionary Grant programs," the Highway Administration said, adding that it is accepting applications to provide $848 million in grants to help improve resilience to climate change impacts. 

"So the question is, when do we learn to adapt, to make sure that the investments that we do pay back?" Jacob said. "...We have to fight this issue on many different fronts simultaneously. ... It's not just the adaptation side that we have to look at. We also have to reduce our fossil fuel use and therefore make things not worse in the future." 

In:
• Weather Forecast
• Climate Change
• Road Conditions
• Infrastructure
• New York