[gregpark]

^ you could be right and yes, it's left to the discrepancy of the CHP officer in charge of passage. I was just commenting on the signage. But there is a difference between M+S and A/T tires. Mud and Snows with a more aggressive tread (more air space in the tread) are louder and wear faster on dry pavement but definately work better in deep snow on my off road Jeep. I've also run some A/Ts that performed really well (better than M+S) on icy roads in my 4x4 truck. The CHP are looking for worn out tires too, regardless of the markings.