Truck Weight Limits and Regulations in California

California enforces strict weight limitations on commercial motor vehicles to protect state infrastructure and ensure highway safety. Governed primarily by the California Vehicle Code (CVC) Division 15, Chapter 5, the standard maximum gross vehicle weight (GVW) on California highways is 80,000 pounds. This limit applies to combinations of vehicles with five or more axles. However, compliance is not determined solely by total weight; vehicles must also adhere to specific axle weight limits and the bridge formula, which calculates the allowable weight based on the distance between axle groups. Operators must be aware that local jurisdictions may impose lower weight restrictions on specific streets or bridges, often marked with regulatory signage. Navigating these complex regulations requires precision to avoid costly citations and delays at California Highway Patrol (CHP) inspection facilities. DispatchTool integrates these California-specific weight parameters directly into its truck-safe routing engine, ensuring dispatchers only assign loads that comply with the 80,000-pound GVW and specific axle spacing requirements. By calculating routes that bypass restricted bridges or local weight-limited roads, the platform helps drivers maintain legal operations across the state. Create a DispatchTool account to start planning routes that automatically account for California weight restrictions and bridge formula compliance.

Standard Axle Weight Maximums

Under CVC Section 35550, the maximum weight allowed on any single axle is 20,000 pounds. For tandem axles, defined as two or more consecutive axles whose centers are more than 40 inches but not more than 96 inches apart, the limit is 34,000 pounds. A steering axle is generally limited to 12,500 pounds, though this can vary based on the tire manufacturer's load rating, not to exceed 620 pounds per lateral inch of tire width. If a vehicle exceeds these specific axle thresholds despite being under the 80,000-pound gross limit, it is considered overweight and subject to fines.

California Bridge Table and CVC 35551

California utilizes a specific bridge formula outlined in CVC Section 35551 to determine the maximum weight for any group of two or more consecutive axles. The formula is expressed as W = 500 [LN / (N-1) + 12N + 36], where W is the maximum weight, L is the distance in feet between the extremes of any group of axles, and N is the number of axles in the group. For example, a vehicle with a 51-foot wheelbase (distance between the first and last axle) is permitted the full 80,000 pounds. If the wheelbase is shorter, the allowable gross weight decreases significantly to prevent structural stress on bridge spans.

Kingpin to Rear Axle (KPRA) Requirements

California imposes unique length-to-weight restrictions known as the KPRA limit. For trailers over 48 feet, the distance from the kingpin to the center of the rear axle (or the center of the rear axle group) must not exceed 40 feet for semi-trailers. For trailers 48 feet or less, this requirement does not apply in the same manner, but the 40-foot KPRA is the standard for 53-foot trailers to remain California legal. Drivers often have to slide their tandems forward to meet this 40-foot requirement, which shifts more weight onto the drive axles and requires careful re-weighing to ensure the drives do not exceed 34,000 pounds.

Overweight Permits and Fees

The California Department of Transportation (Caltrans) issues permits for vehicles that cannot be reduced to legal weight limits. Single-trip permits cost $16.00 and are valid for seven days. For frequent haulers, an annual permit costs $90.00. These permits allow for weights exceeding 80,000 pounds, often up to 150,000 pounds or more depending on the axle configuration, provided the load is non-reducible. Extralegal loads must follow specific routes designated by Caltrans and may be restricted from travel during peak commute hours in urban areas like Los Angeles or San Francisco.

Tire Load Limits and Specifications

Weight limits are also constrained by tire capacity under CVC Section 35550. No tire may carry a weight greater than that specified by the manufacturer's rating molded onto the sidewall. Furthermore, the weight exerted on the road surface cannot exceed 620 pounds per lateral inch of tire width. For a standard 11-inch wide truck tire, this mathematically allows for approximately 6,820 pounds per tire, though the 20,000-pound single axle limit remains the primary ceiling. This regulation ensures that even if an axle is rated for high capacity, the tires themselves are not overloaded.

Enforcement and Weigh Station Procedures

The California Highway Patrol (CHP) operates over 50 Commercial Vehicle Enforcement Facilities (weigh stations) across the state. All commercial vehicles with a GVWR of 10,001 pounds or more must stop when stations are open. California uses Weigh-In-Motion (WIM) technology at many sites to screen trucks at highway speeds. If the WIM system detects a potential overweight violation, the driver is signaled to enter the static scales. Fines for weight violations are graduated; a vehicle 1,000 pounds over limit may face a small fine, while a vehicle 5,000 pounds over can face penalties exceeding $1,000 plus court fees.

Sources

California Legislative Information (CVC Division 15) (2024) — https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH&sectionNum=35551 Caltrans Legal Truck Weights and Dimensions (2024) — https://dot.ca.gov/programs/traffic-operations/legal-truck-truck-network California Highway Patrol (CHP) Commercial Vehicle Section (2024) — https://www.chp.ca.gov/programs-services/programs/commercial-vehicle-section

Frequently asked

What is the maximum gross weight for a 5-axle semi-truck in California?

The maximum gross vehicle weight is 80,000 pounds, provided the vehicle meets the bridge formula requirements and axle spacing limits defined in CVC 35551.

What is the KPRA limit for 53-foot trailers in California?

For a 53-foot trailer, the distance from the kingpin to the center of the rear axle must not exceed 40 feet. This is a critical measurement for legality on most California highways.

How much does a California overweight permit cost?

A single-trip permit for an overweight or oversized load costs $16.00, while an annual permit is available for $90.00 through Caltrans.

Are there weight tolerances in California?

California does not provide a formal statutory weight tolerance; however, CVC 35551.5 allows for minor variances in specific agricultural hauls, but general freight must strictly adhere to the 80,000-pound limit.

What are the tandem axle weight limits in California?

Tandem axles are limited to 34,000 pounds total, provided the axles are spaced between 40 and 96 inches apart.