Truck Weight Limits and Permitting in Arkansas

The Arkansas Department of Transportation (ARDOT) enforces strict weight limitations on commercial motor vehicles to preserve the state's 16,400 miles of highway infrastructure. For standard operations, Arkansas follows federal bridge formula standards on Interstate highways, while specific state statutes govern non-Interstate routes. The maximum gross vehicle weight (GVW) allowed without a special permit is 80,000 pounds. These regulations are enforced by the Arkansas Highway Police through both fixed weigh stations and mobile enforcement units using portable scales. Understanding these limits is critical for carriers to avoid significant fines and delays. DispatchTool assists carriers in maintaining compliance by integrating these state-specific weight restrictions into its truck-safe routing engine. When dispatchers input load weights, the platform calculates total GVW and maps routes that avoid weight-restricted bridges and secondary roads not rated for heavy axle loads. This helps drivers stay on legal paths and provides a central location for storing oversized/overweight (OSOW) permits. To streamline your Arkansas route planning and permit management, create a DispatchTool account.

Standard Maximum Weight Limits

In Arkansas, the legal weight limits for commercial vehicles are categorized by axle configuration. A single axle is limited to 20,000 pounds, while a tandem axle (two axles spaced more than 40 inches but no more than 96 inches apart) is limited to 34,000 pounds. For vehicles traveling on Interstate highways, the gross weight is capped at 80,000 pounds. On non-Interstate highways, the limit is also 80,000 pounds, provided the vehicle meets the requirements of the Federal Bridge Formula. According to Arkansas Code § 27-35-203, any vehicle exceeding these specific thresholds must obtain an overweight permit before entering the state's roadway system.

Bridge Formula Calculations

Arkansas utilizes the Federal Bridge Formula B to determine the maximum allowable 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 overall gross weight, L is the distance in feet between the extremes of any group of two or more consecutive axles, and N is the number of axles in the group under consideration. This calculation prevents concentrated heavy loads from damaging bridge spans. Even if a truck is under the 80,000-pound total limit, it may still be cited if a specific axle group is spaced too closely for the weight it carries.

Overweight Permit Types and Fees

For loads that cannot be reasonably dismantled, ARDOT issues several types of overweight permits. A single-trip overweight permit generally costs $10.00 plus an additional mileage fee if the weight exceeds certain thresholds. For example, if a vehicle exceeds the 80,000-pound limit, the state charges $0.08 per ton-mile for the excess weight. Annual permits are available for specific commodities, such as sealed containers for international trade or specialized equipment, typically ranging from $100.00 to over $500.00 depending on the specific exemption. All permits must be carried in the vehicle, either in physical or electronic format, during the entire duration of the trip.

Seasonal and Secondary Road Restrictions

Arkansas periodically implements temporary weight restrictions on secondary highways, particularly during the spring thaw or periods of heavy rainfall. The Highway Commission has the authority under AR Code § 27-35-103 to reduce weight limits by up to 50% on specific roads to prevent total pavement failure. These restricted routes are often posted with signage indicating a 10-ton or 15-ton limit. Carriers must actively monitor ARDOT's 'IDriveArkansas' portal to identify these temporary bans. Operating a heavy commercial vehicle on a posted restricted road can lead to immediate impoundment and fines exceeding $1,000.00.

Weight Enforcement and Penalties

The Arkansas Highway Police (AHP) operates 12 permanent weigh stations across the state and utilizes mobile weigh teams. Penalcy structures for weight violations are graduated based on the degree of excess. According to the ATRI, fines are calculated per pound of excess weight. For example, an overweight violation of 1,000 to 2,000 pounds may result in a fine of one cent per pound, while violations exceeding 10,000 pounds over the limit can cost up to 10 cents per pound. In addition to fines, drivers are often required to offload excess weight or shift the load to become legal before the vehicle is allowed to proceed, resulting in significant logistical costs.

Agricultural and Logging Exemptions

Arkansas provides specific weight allowances for vehicles transporting raw forest products or agricultural commodities from the point of harvest to the first point of marketing. Under AR Code § 27-35-208, these vehicles are allowed a 5% variance on non-interstate highways, effectively raising the tandem axle limit to approximately 35,700 pounds. However, this variance does not apply to the 80,000-pound gross weight limit unless the carrier has purchased a specific commodity permit. It is also important to note that these exemptions are strictly prohibited on the Interstate system, where federal 80,000-pound caps remain absolute.

Sources

Arkansas Department of Transportation (ARDOT) (2024) — https://www.ardot.gov/divisions/highway-police/permits/ Arkansas Code Title 27, Chapter 35 (2023) — https://law.justia.com/codes/arkansas/2023/title-27/subtitle-2/chapter-35/ American Trucking Research Institute (ATRI) - Arkansas State Laws (2024) — https://truckingresearch.org/

Frequently asked

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

The maximum legal gross vehicle weight for a standard 5-axle semi-truck in Arkansas is 80,000 pounds, provided the axle spacing complies with the Federal Bridge Formula.

How much does an overweight permit cost in Arkansas?

A basic single-trip overweight permit starts at $10.00, but additional ton-mile fees of $0.08 per ton-mile apply for loads exceeding standard limits.

Are there weight tolerances for agricultural loads in Arkansas?

Yes, Arkansas allows a 5% weight variance for vehicles hauling raw agricultural or forest products on non-Interstate roads, though this does not increase the federal 80,000-pound cap on Interstates.

What is the weight limit for a single axle in Arkansas?

The maximum legal weight for a single axle in Arkansas is 20,000 pounds on both Interstate and non-Interstate highways.

Where can I buy an Arkansas OSOW permit?

Permits can be purchased online through the ARDOT Permit Portal or at designated AHP weigh stations; the permit office is open Monday through Friday, 8:00 AM to 4:30 PM CST.