What happens when a major urban freeway burns down? Chaos, right? Gridlock! Except not:

Traffic congestion was down Monday and Tuesday. The amount of time drivers were stuck in traffic moving slower than 60 mph was down 8 percent around the entire Bay Area, according to Caltrans data. Congestion on Oakland freeways, meanwhile, was down by more than 50 percent, the data showed.

BART ridership, meanwhile, spiked dramatically, hitting an all-time record on Tuesday. The number of BART commuters was up 10.4 percent Tuesday and 5.2 percent Wednesday morning; no figure was available for Monday, when fares were waived.

“It doesn’t seem like travel times were getting worse; in fact, in some cases, they actually seemed to be getting better,” said Karl Petty, an engineer who heads [Berkeley Transportation Systems].

Petty said a small percentage of drivers staying off the roads can make a huge difference in lowering traffic congestion — not just at the freeway collapse site, but around the region. This week’s changes by a few drivers along key routes seemed to make a big difference, according Caltrans data from thousands of buried freeway sensors.

Imagine if we did something crazy like that on purpose!