I happen to have been in Washington DC the night before the great Metro shutdown. It appears that some power cables were bad and had to be replaced quickly over safety concerns. The night before local TV news was full of the usual traffic doomsday coverage. Who would go to work? How? Would lateness to school be excused? (Yes) Would teleworking be allowed? (Yes). How much surge pricing would Uber require?
The next morning, I took an Uber from Georgetown to Dulles for just over $40 in just over 30 minutes. No surge pricing. No traffic. My driver mentioned that there had been no problem all morning.
It was about the same when LA's 405 shut down for 24 hours recently. "Carmageddon" came and went; the hype and fears were wrong. Note this from the Wikepdia coverage: "In reality, traffic was lighter than normal across a wide area ..." It was also this way back in 1984 for the LA Olympics. Traffic doomsday never came. People are not stupid and make all sorts of plans and adjustments.
Doomsday predictions have a long history of being wrong. But people do like to worry. This tendency seems to overcome credibility concerns. Will climate change cause massive coastal flooding? Have beachfront property values been falling or rising?