Different kinds of roads behave very differently under heat. In the US, roads are typically made of one of two materials — asphalt or concrete. “You can’t design for everything. Some things just break your infrastructure.” “It’s just sort of wait for something to break and then fix it when it breaks.”
And that's what happened across the Pacific Northwest - the extreme heat not only buckled roadways; it killed hundreds of people. Many were simply not expecting it to be so hot for so long, and air conditioning is relatively uncommon here. Many who died were at home, with no A/C. Our climate is generally mild, so residences are built more to withstand strong winds and the occasional cold snaps.
“That’s why Phoenix isn’t falling apart — it’s not Armageddon there because it’s hotter.”
The problem is that when some of these roads in Washington state were being designed, using those materials or design techniques would have been overkill — the area doesn’t normally get as hot as Phoenix, so there was no need to build with extreme heat in mind.