Heat and Humidity May Wreak Havoc on Roads

(KNSI) — The Minnesota Department of Transportation is warning our short but intense hot weather could lead to pavement buckles.

Highs Tuesday and Wednesday are expected to be into the 90s with heat index values into the triple digits. MNDOT says roads are constructed to allow for expansion and contraction, and the warmer the temperature, the more the materials expand. Experts say the sun heats the road surface, and in some cases, especially in older concrete or weaker roads, there isn’t enough space to accommodate expansion, so it buckles.

Road heaves are extremely dangerous and can act like a ramp, launching vehicles and causing them to go out of control and crash. If a driver comes across one, slow down, but don’t drive over it. Instead, move to another lane and call 911 when it’s safe.

St. Cloud Public Services Director Tracy Hodel told KNSI News that warm weather is good for road work, but it’s harder to fix potholes and seal roads if it’s too hot. “We’re around that threshold where it’s good temperatures because it’s warm, but then towards the middle of the day when it’s really hot, that’s when you’re going to see where we want to limit that to make sure it’s not too hot when we’re applying those products.”

Hodel says high temperatures cause separation in oils used in the materials to fix the roads. “It just takes longer to cool because it’s hotter outside. And so with that, you could see some issues with not getting the application that you want because you open up the road too early, and you have vehicles going over there and picking some of that up on their tires.”

The sweltering weather also takes its toll on the equipment. Excess heat makes machinery work harder, and even the oils used to lubricate moving parts have a temperature threshold before they separate or break down. Other plastic or rubber parts can become brittle or crack.

Hodel says the crews will get out early in the morning and be done for the day before the mercury hits the blazing hot temperatures.

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