On I 80, I've never gotten anything more than a wave nor slowed to a stop in any vehicle I've ever taken through chain controls. Nor any vehicle in which I've been a passenger . This includes vehicles with chains, 4wd with M+S tires, and 4wd with snow tires. There's no way the Caltrans dude could see the marks on the tires to know they were appropriate, and there's no way he knew if I had chains in the car or not. There's usually a 60 to 90 minute backup at the checkpoints; they don't have time to make every car stop without creating even more massive backups. The morons in their cars with no awd and no chains cause enough delays. If you look "good enough" from a distance, they'll wave you through. And, then fine you thousands of dollars if you're in an incident without proper equipment.