JUANA SUMMERS, HOST:
Tens of millions of people across the United States are currently under a heat advisory, and the extreme heat isn't just affecting people. You may have seen videos online of the heat causing asphalt roads to buckle, creating bumps in the ground. The heat is impacting rail travel, too. Amtrak has been running some of its trains more slowly, as have the public transit systems in Washington, D.C., and Philadelphia.
Mikhail Chester has thought a lot about extreme heat and transportation. He's an engineering professor at Arizona State University, where he studies the impacts of climate change on transportation infrastructure. Welcome to ALL THINGS CONSIDERED.
MIKHAIL CHESTER: Thanks - delighted to be here.
SUMMERS: Okay, I'd love to start, if we can, with roads and trains. Can you start by just telling us briefly - how does extreme heat affect train tracks, for example, or make the road expand? What exactly is happening there?
CHESTER: Yeah, so there's sort of two dynamics to think about. One is the impact directly to the infrastructure itself. And, in many ways, we've designed our infrastructures over decades, if not centuries, for temperatures that have been relatively milder. So when it comes to a road, we design roads with a particular temperature extreme in mind, depending on the particular location where that road is built and maintained. And now, as temperatures are hotter, you're starting to see the dynamics of those extremes take hold, exceeding the design thresholds of those infrastructures and their particular assets.
So you might experience more cracking and rutting when it comes to a road. When it comes to rail, you might experience that the thresholds of the thermal expansion joints of the rail tracks are being exceeded. And even if the infrastructure itself is not impacted, simply the threat of the failure is resulting in transit agencies or transportation agencies in general having to look out for these threats.
SUMMERS: We've talked a little bit about roads and trains, but are there other examples you could give us about ways that extreme heat can impact the country's transportation infrastructure and the people who depend on it?
CHESTER: Sure. So you have started to see stories pop up of airport impacts to service operations where, you know, planes and pilots are told to essentially adjust how much distance they need to take off, and that has had an impact on service and operations. But also, there's a human side to this. So people who operate transportation infrastructure...
SUMMERS: Yeah.
CHESTER: ...who are outside also are impacted by these heat waves. You know, we need to keep them in reprieve for a little bit longer and make sure that, you know, they are ultimately safe. A common story that we might hear about is how passengers on transit vehicles, for example, might be more unruly more often, leading to police intervention. So all of these things are at play and ultimately may have some impact into the service.
SUMMERS: So Mikhail, to your mind, is this a moment to say that we need to change our approach?
CHESTER: Correct. Now is a time when we're starting to see innovation emerge and also limitations of how much we can engineer ourselves using existing models of how we typically approach infrastructure, whereas, in the past, we may have said we'll simply update to hotter temperatures in how we design. The challenge of doing that is there's so much infrastructure out there, and the costs of rehabilitating might be quite expensive. And as such, we're starting to see folks ask this question of - what could we do differently?
SUMMERS: I wonder if you have a message to policymakers or others who are approving budgets in order to make cities more resilient. Is there one thing in particular they should think about as they're trying to figure out how to address this?
CHESTER: I would say that, as we enter this period where we're experiencing these climate hazards - heat and otherwise - we're starting to see that there's a major market for producing knowledge to be able to address these challenges. Often, the way that we've been doing it in the past doesn't seem to be sufficient for how we need to approach infrastructure in the future. We need to pivot how we're approaching this challenge. And that's going to require us to innovate, which we are doing. It's going to require us to share that knowledge, which we're starting to do.
SUMMERS: One thing you said that really stuck with me is the fact that, yes, this is about infrastructure in terms of rails and roads and buses and cars, but it is also about the people who are doing the work - the people who are helping us all get from place to place and operating these transit systems. I wonder - is there something that can be done to protect those people in this moment where climate change is making life on planet Earth hotter for all of us?
CHESTER: We need to make sure that we have the latest knowledge and science to be able to protect them. For example, how long is it safe for them to be outside in heat waves relative to how long do they need to come into air conditioning for reprieve? Secondly, the giving - arming them with the appropriate knowledge of how they should respond to these disasters and threats becomes really important.
SUMMERS: That's Mikhail Chester, engineering professor at Arizona State University. Thank you so much.
CHESTER: Thank you very much. Transcript provided by NPR, Copyright NPR.
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