Unfortunately the state of Illinois believes that SCOTUS ruled them legal under a very narrow scope.
https://www.tmj4.com/news/project-drive-sober/roadside-checkpoints-legal-tool-or-illegal
Thanks for citing that. I wish that particular site would have cited the information more specifically, but who can be bothered to read the actual decision?
https://www.justice.gov/sites/default/files/osg/briefs/1989/01/01/sg890414.txt