They were setting testing check points in major highways. It wasn't a full lockdown, because they tested everyone and had enough information to be able to contain it effectively.
And more competently. They actually managed to make enough tests in time and use them on all known contacts of any infected individual. We're long past the point of that being remotely possible in the US.
The main stupid thing we did was very little testing. Our genius prez kept saying it was no big deal, and they followed policies that in retrospect make it look like they were trying to test less. At least the effective situation in the end was the entire us country has 100 times less testing that the tiny country of S.K.
If we had testing and actively tested 2 months ago we'd have see the problems and started dealing with them more aggressively. We stupidly seemed to follow a policy of no visible harm, no preperations necessary.
how does that work out since S Korea is linked with the outside world? Is it sustainable for as long a the virus in out in the world? I guess that they stopped this round...if tens or hundreds of millions in the world have it, game over.
"If you can't measure it, you can't improve it"