CSA and Tire Basics
Serious tire violations
The Commercial Vehicle Safety Alliance is an organization of state departments of transportation and police that create uniform inspection criteria for the U.S., Canada and Mexico. The most serious CVSA tire violations are:
• Tire flat or with audible air leak;
• Tread and/or sidewall separation;
• Fabric exposed;
• A cut in the sidewall that exposes the ply or belt material;
• Tread depth less than 2⁄32-inch for trailer and drive tires, and 4⁄32-inch for steer tires.
Somewhat less serious violations include:
• Inadequate weight rating;
• Tire underinflated;
• Tire underinflated for the weight being carried;
As these violations indicate, it’s preferable to adjust tire pressure for the load. For example, if running empty for a long distance, it would be better to lower tire pressure slightly to avoid irregular wear in the center of the tread. A chart showing pressure adjustments is available from tire manufacturers.
Pressure adjusted below the maximum but down to a level appropriate for load conditions would not be a violation. On the other hand, if your rig is loaded to 80,000 pounds, the same lower pressure could get you a citation. Even a tire in good condition can lead to a citation if its maximum load rating is less than the weight it is carrying.
Use of an obviously re-grooved tire on the steer axle is another violation. This should rarely be a concern these days, as most owner-operators and small fleets rarely re-groove tires.