In California, the truck speed limit is 55 mph on every highway in the state, regardless of whether the road is posted at 65 or 70 for cars. Vehicle Code 22406 sets that ceiling for specific heavy and higher-risk vehicles, creating a two-tier system where passenger cars follow the posted number and covered trucks do not.1California Legislative Information. California Code VEH 22406 – Speed Laws
Which Vehicles Are Capped at 55
Vehicle Code 22406 lists the vehicles that cannot exceed 55 mph on any California highway:
- Any motortruck or truck tractor with three or more axles
- Any motortruck or truck tractor pulling another vehicle
- Any passenger vehicle or bus towing another vehicle
- Any school bus carrying pupils
- Any farm labor vehicle carrying passengers
- Any vehicle hauling explosives
- A trailer bus (designed to be pulled by another vehicle)
The common thread is size, weight, or cargo risk. These vehicles need more distance to stop and handle differently at speed than a sedan.1California Legislative Information. California Code VEH 22406 – Speed Laws
Two-Axle Trucks and What Towing Changes
A standard two-axle pickup or box truck driving on its own is not subject to the 55 mph cap. Section 22406 only reaches motortrucks with three or more axles, or any motortruck pulling something. A two-axle truck driving solo follows the posted limit like any car.
Hitch a trailer to that same pickup and the 55 mph limit takes effect. The trigger is the act of towing, not the truck’s weight rating. This catches recreational drivers off guard: towing a boat or travel trailer on a highway posted at 65 means your legal maximum drops to 55.
How 55 Interacts With Lower Posted Limits
The 55 mph cap is a ceiling, not a floor. When a covered vehicle enters an area with a lower posted speed, the lower number controls. A 45 mph construction zone, a 35 mph surface road, and a 25 mph school zone all override the 55 mph maximum.
California’s Basic Speed Law, Vehicle Code 22350, adds another layer. Every driver must travel at a speed that is reasonable for current conditions no matter what any sign says. Rain, fog, heavy traffic, or a narrow road can make 55 mph dangerously fast, and an officer can cite a truck driver going 50 in a 55 zone if conditions made that speed unsafe.2California Legislative Information. California Code VEH 22350 – Speed Laws
The working rule: follow whichever limit is lower, and drop below that if conditions demand it.
Lane Restrictions That Come With the Cap
Covered vehicles also face lane rules under Vehicle Code 21655. Where Caltrans or a local authority has posted signs designating specific truck lanes, those vehicles must use them. Where no truck lanes are posted, covered vehicles must stay in the far-right lane or as close to the right edge as practical.3California Legislative Information. California Code VEH 21655 – Designated Lanes for Certain Vehicles
Exceptions cover drivers preparing for a left or right turn, entering or exiting the highway, or following a route the right lanes do not serve. Drifting left outside those situations can add a lane citation on top of any speeding ticket.
Fines and Points for a 22406 Ticket
The base fine on a Vehicle Code 22406 violation is small, but penalty assessments and surcharges multiply it by roughly five times. From California’s Uniform Bail and Penalty Schedule:
- 1 to 9 mph over 55: $85 base fine, roughly $439 total.
- 10 mph or more over 55: $135 base fine, roughly $644 total.
Those totals include state and county penalty assessments, a DNA identification fund assessment, court operations fees, a conviction assessment, and other add-ons.4California Courts. Uniform Bail and Penalty Schedules
A conviction also adds one point to the driver’s record under Vehicle Code 12810, like most moving violations. Enough points trigger the DMV’s negligent operator process.5California Legislative Information. California Code VEH 12810 – Violation Point Count
Extra Consequences for CDL Holders
Commercial drivers carry more risk than the fine suggests. Under federal law, speeding 15 mph or more above the limit in a commercial motor vehicle counts as a “serious traffic violation.” Two serious violations within three years triggers a minimum 60-day CDL disqualification. Three within three years raises it to at least 120 days.6Office of the Law Revision Counsel. 49 USC 31310 – Disqualifications
Disqualification means lost income, possible termination, and a record future employers will see. For a professional driver, a single truck-speed ticket deserves serious attention, because the second one inside three years carries career consequences.