South Dakota Weigh Stations and Port of Entry Regulations

South Dakota operates a comprehensive network of fixed scale locations and mobile enforcement units managed by the South Dakota Highway Patrol’s Motor Carrier Services. The state serves as a primary transit corridor for East-West traffic on Interstate 90 and North-South traffic on Interstate 29. All commercial motor vehicles with a Gross Vehicle Weight Rating (GVWR) of 8,000 pounds or more are required to pull into open weigh stations and ports of entry. This threshold is lower than the federal 10,001-pound standard used in many other states, making it critical for operators of medium-duty trucks to remain compliant while traversing the state. Compliance in South Dakota involves adhering to strict bridge formula weights and axle limits to preserve the integrity of state infrastructure. DispatchTool helps carriers manage these requirements by providing truck-safe routing that accounts for permanent scale locations and restricted routes. By integrating dispatch data with specific state bridge laws, the platform ensures drivers are aware of upcoming ports of entry and have their electronic documentation ready for inspection. Drivers can create a DispatchTool account to centralize their trip planning and weight compliance logs.

Primary Port of Entry Locations

South Dakota maintains major Ports of Entry at key border crossings to monitor interstate commerce. The Sioux Falls Port of Entry on I-29 Northbound (Mile Marker 62) and Southbound (Mile Marker 85) handles heavy volume from Iowa and North Dakota. On I-90, the Tilford Port of Entry (Mile Marker 40) serves Westbound traffic near the Black Hills, while the Valley Springs Port of Entry (Mile Marker 412) monitors Eastbound traffic entering from Minnesota. These facilities are generally staffed 24 hours a day and utilize Weigh-in-Motion (WIM) technology to prescreen vehicles before they reach the static scale. Motor carriers must watch for the 'All Trucks Must Enter' signs, which are activated when the facility is operational.

Weight Limits and Bridge Formula Requirements

South Dakota follows the Federal Bridge Formula B for weight limits on the Interstate System, but enforces specific state laws for secondary highways under SDCL 32-22. The maximum gross vehicle weight on interstates is 80,000 pounds unless the vehicle has specific permits. Single axles are limited to 20,000 pounds, and tandem axles are limited to 34,000 pounds. For non-interstate highways, the weight per inch of tire width is restricted to 600 pounds for the steering axle and 500 pounds for all other axles. During the spring thaw, typically from February 15 to April 30, the South Dakota DOT may implement 6-ton or 7-ton per axle limits on specific secondary routes to prevent pavement damage.

Electronic Bypass Programs: PrePass and Drivewyze

To improve freight efficiency, South Dakota participates in the PrePass and Drivewyze bypass programs. These systems allow qualified carriers with high safety scores (ISS) to bypass scales without stopping, provided their weight and credentials are verified electronically. Approximately 8 sites in South Dakota are equipped with PrePass technology, including locations at Jefferson, Sioux Falls, and Tilford. According to the South Dakota Highway Patrol, bypassing a scale saves an average of 5 minutes and 0.4 gallons of fuel per pull-in. However, even with a green light, drivers must still obey 'Random Pull-In' commands if indicated by the in-cab transponder or mobile device.

Permit Requirements and Fees

Vehicles exceeding standard dimensions or weights must obtain permits through the South Dakota Department of Revenue. A single-trip permit for an overweight vehicle costs $25 plus $0.02 per ton-mile for every ton over the legal limit. For over-width loads, the fee is $25 per trip. South Dakota also offers an annual 'Harvest Permit' for $200, allowing a 10% weight increase for hauling agricultural products from the field to the first point of storage. Carriers must ensure that all permit documentation is available for inspection at the Port of Entry, as failure to produce a valid permit results in fines ranging from $100 to over $1,000 depending on the degree of the violation.

Oversize Load Escort Regulations

South Dakota Administrative Rule 70:03:01:20 dictates escort requirements for large loads. An escort vehicle is required for any load exceeding 14 feet in width on two-lane highways or 16 feet in width on divided highways. For lengths exceeding 110 feet, a rear escort is mandatory. Escort drivers do not need a specific South Dakota certification but must possess a valid driver's license and follow standard safety lighting protocols. Movement of oversize loads is generally prohibited from sunset to sunrise and during severe weather conditions when visibility is less than 500 feet, as determined by the Highway Patrol.

Safety Inspections and CVSA Levels

The South Dakota Highway Patrol conducts North American Standard Inspections at all Port of Entry locations. In 2023, inspectors performed thousands of Level I (North American Standard), Level II (Walk-Around), and Level III (Driver-Only) inspections. A Level I inspection covers 37 steps, including a detailed check of the braking system, tires, and the driver's Record of Duty Status (RODS). If a vehicle is found to have a Category 1 violation, such as a 20% brake failure, it will be placed Out-of-Service (OOS). The ATRI reports that the average cost of a non-accident OOS order is approximately $4,000 per day in lost revenue and repair costs.

Sources

South Dakota Highway Patrol Motor Carrier Services (2024) — https://hp.sd.gov/motorcarrier/ South Dakota Department of Transportation - Commercial Vehicles (2024) — https://dot.sd.gov/doing-business/permits/truck-permitting South Dakota Codified Laws Title 32 Chapter 22 (2023) — https://sdlegislature.gov/Statutes/Codified_Laws/2056073

Frequently asked

What is the weight limit for trucks to bypass a scale in South Dakota?

All vehicles with a GVWR of 8,000 pounds or more must stop at South Dakota weigh stations unless they are using an authorized bypass program like PrePass or Drivewyze and receive a green light.

Are South Dakota weigh stations open on weekends?

Yes, major Ports of Entry such as Valley Springs and Jefferson are typically open 24 hours a day, 7 days a week, including weekends and holidays.

What is the fine for bypassing a weigh station in South Dakota?

Bypassing an open scale is a Class 2 misdemeanor in South Dakota, which can carry a fine of approximately $200 plus court costs and potential points on a CDL.

Does South Dakota allow triple trailers?

Yes, South Dakota allows Long Combination Vehicles (LCVs), including triples, on designated routes with a permit. The maximum overall length for a triple trailer setup is 110 feet.

How much does a temporary fuel permit cost in South Dakota?

If a carrier is not IFTA-registered, a 72-hour temporary fuel permit costs $20 and must be obtained before or immediately upon entering the state.