IANAL, but I believe this also allows the cops to set up random DUI roadblocks (ie, untargeted, no warrant, no individual suspicion, public good, etc).
Those roadblocks clearly haven't been ruled unconstitutional (they happen in Illinois all the time), but it's worth noting that they're set up expressly in the service of criminal investigations, which is exactly what admin searches aren't supposed to be about.
For slightly more context, note that there is a scheme of "primary" and "secondary" moving violations, which is why technically you're not supposed to be able to get pulled over for not having your seatbelt on.
Mostly what they're doing at those checkpoints is racking up compliance tickets, which is obviously a load of BS.
Fortunately, this is a problem easily addressed by technology.
A few months back I went thru just such a 'safety check'. It was on the state line between Alabama and Georgia. Alabama had ~15 units and a portable command post stopping all the traffic east bound into Georgia, while Georgia had ~20-25 units stopping all the traffic west bound into Alabama.
They took my license, insurance, examined them carefully, then walked around and looked at my license plate, handed them back (with a smile) and said to have a nice evening. I've never seen so many blue lights in one place in my life.
A few days later I described this to a Florida Highway patrol trooper. He chuckled and said it sounded like someone wanted to look good for the 11 o'clock TV news.
