Truck Lane Use
Summarized here are the California Vehicle Code (CVC) sections related to highway lane use for trucks. The CVC text is copied here with bolding added and slight editing for brevity. For the full legal wording, please use the links to the on-line CVC.
The following CVC section lists the vehicles that must drive at reduced speeds:
22406. No person may drive any of the following vehicles on a highway at a speed in excess of 55 miles per hour:
(a) A motortruck or truck tractor having three or more axles or any motortruck or truck tractor drawing any other vehicle.
DESIGNATED LANES for VEHICLES with a 55 MPH SPEED LIMIT
Vehicles that are required to travel at a maximum of 55 mph on California highways must use a designated lane or lanes, as stated in the CVC below:
21655. (a) ... (b) Any ... vehicle subject to the provisions of Section 22406 shall be driven in the lane or lanes designated ... whenever signs have been erected... . ..., when a specific lane or lanes have not been so designated, ... those vehicles shall be driven in the right-hand lane for traffic or as close as practicable to the right edge or curb. If, however, a specific lane or lanes have not been designated on a divided highway having four or more clearly marked lanes for traffic in one direction, ... those vehicles may also be driven in the lane to the immediate left of that right-hand lane, ... When overtaking and passing another vehicle proceeding in the same direction, the driver shall use either the designated lane, the lane to the immediate left of the right-hand lane, or the right-hand lane for traffic ... This subdivision does not apply to a driver who is preparing for a left- or right-hand turn or who is entering into or exiting from a highway or to a driver who must ... drive in a lane other than the right-hand lane to continue on his or her intended route.
DESIGNATED LANES for SLOWER MOVING VEHICLES
The following CVC section also mentions using the right-hand lane for slower moving vehicles:
21654. (a) ..., any vehicle proceeding upon a highway at a speed less than the normal speed of traffic moving in the same direction ... shall be driven in the right-hand lane for traffic or as close as practicable to the right-hand edge or curb, except when overtaking and passing another vehicle proceeding in the same direction or when preparing for a left turn at an intersection or into a private road or driveway.