California Chain Controls: What Each Truck Configuration Has to Fit
Date Published
California does not run one rule for heavy vehicles. It runs a table, and where you fall in it depends on how the vehicle is put together.
When it binds
13 CCR 1072 applies when the California Department of Transportation or a local authority posts an official traffic control device requiring the use of chains or chain control due to inclement weather and highway conditions. It is a chain control, not a calendar.
Trucks and truck tractors
For a two axle motor truck over 10,000 lb, tire traction devices must be installed on at least two tires of a drive axle. For a three axle motor truck, at least four tires of the drive axles.
For a truck tractor, whether two axle or three axle, the devices must be installed on at least four tires of the drive axles.
Combinations
A truck tractor pulling a semitrailer must have at least four tires of the drive axles equipped, and on the semitrailer at least two tires of one axle.
Add a second trailer and the requirement extends. A two axle truck tractor with a semitrailer and a trailer needs four tires of the drive axle equipped, two tires of one semitrailer axle, and two tires of the rear-most trailer axle. On a three axle truck tractor in the same configuration, the split is four tires of the forward drive axle and two tires of the rear drive axle.
The configuration that can be excluded entirely
Subsection (d)(2)(A) is the provision worth knowing before you plan a winter route. Single drive two axle truck tractor, semitrailer and trailer combinations are prohibited from designated chain control areas when traffic control signs are posted prohibiting that specific type of vehicle combination.
That is not a chain requirement. It is an exclusion. No amount of equipment makes that combination legal on the segment while the sign is up, so the answer is a different route rather than more chains.
Buses and lighter vehicles
The same section covers buses, requiring devices on at least two tires of the drive axle of a two or three axle bus, with an articulated three axle bus also needing two tires of the rear-most axle. Vehicles under 10,000 lb, including all-wheel and four wheel drive, need devices on at least two tires of a drive axle.
A sourcing note
The regulation text was read through a commercial mirror of the California Code of Regulations, current through Register 2025, Notice Reg. No. 26. The official CCR is published on a platform that does not serve retrievable text, so this should be re-verified before it is relied on for a compliance decision. The underlying statutory duty is Cal. Veh. Code 27459.