The South Carolina State Transport Police is the sole law enforcement organization in South Carolina for enforcing both federal regulations and state laws pertaining to commercial motor vehicles (CMVs). Although STP officers specialize in commercial motor vehicle enforcement, they also enforce state traffic laws for non-commercial drivers regularly.

STP’s major objectives are to protect the motoring public by: 

• preventing collisions;
• removing unsafe drivers and vehicles from our roads;
• protecting our environment from hazardous materials being transported on our roadways; and
• preventing the premature deterioration of our roads and bridges through the STP Size and Weight Enforcement Program.

STP officers work throughout South Carolina’s 46 counties, patrolling all our highways and interstates for unsafe commercial motor vehicles and commercial drivers, as well as all unsafe vehicles, to help protect the public daily. 

STP works hand-and-hand with all divisions of the Department of Public Safety, including the South Carolina Highway Patrol and the Bureau of Protective Services. STP also works in close partnership with the Federal Motor Carrier Safety Administration, the Federal Highway Administration, the Commercial Vehicle Safety Alliance, the South Carolina Trucking Association, the South Carolina Department of Motor Vehicles, and the South Carolina Department of Transportation, as well as other state and local law enforcement agencies.

STP Size and Weight Enforcement Program 

Commercial motor vehicle means any self-propelled or towed motor vehicle used on a highway in interstate commerce to transport passengers or property when the vehicle—

1. Has a gross vehicle weight rating or gross combination weight rating, or gross vehicle weight or gross combination weight, of 4,536 kg (10,001 pounds) or more, whichever is greater; or
2. Is designed or used to transport more than 8 passengers (including the driver) for compensation; or
3. Is designed or used to transport more than 15 passengers, including the driver, and is not used to transport passengers for compensation; or
4. Is used in transporting material found by the Secretary of Transportation to be hazardous under 49 U.S.C. 5103 and transported in a quantity requiring placarding under regulations prescribed by the Secretary under 49 CFR, subtitle B, chapter I, subchapter C.

Large commercial motor vehicles are essential for business and economy, transporting thousands of goods across South Carolina every day. However, the size and weight of these vehicles can pose increased risks for everyone on the highway if not respected properly. The overall size and weight of CMVs reduces the vehicle’s handling and increases its stopping distances, which increases the likelihood of collisions, especially in adverse conditions. Strict enforcement of weight regulations for large CMVs is critical to reduce these risks and ensure safer highways for all drivers.

When trucks are overloaded, the dangers to both infrastructure and public safety increase significantly. Vehicles that exceed legal weight limits place an additional strain on roads and bridges, accelerating wear and increasing the risk of structural failures. Furthermore, overweight trucks have adverse environmental costs through increased fuel consumption. 

State Transport Police officers perform size and weight inspections on trucks traveling through the state to help keep CMV drivers, other motorists, and the state’s highway system safe from these risks. Through many  scale facilities and roadside enforcement efforts, STP conducts an average of 50,000 to 60,000 inspections annually. From these enforcement efforts, more than 14,000 unsafe vehicles and drivers are removed from our roadways each year.

Size and Weight Program Resources 

• South Carolina Size and Weight Guidelines (PDF) | SCDOT
• Map of Load Restricted Bridges in South Carolina | SCDOT
• Oversize Overweight Permits | SCDOT
• STP Escort Request Form
• Pay a Citation (for size, weight, and safety violations)

STP Specialized Units 

In addition to size and weight enforcement and regular patrols, the State Transport Police has specialized teams to ensure highway safety across various areas. Read more about these special enforcement units below. 

HAZMAT/Level VI Team 

STP’s HAZMAT/Level VI team are some of the most highly trained officers in the field of hazardous materials, radioactive materials, and transuranic waste regulations. This unit helps to ensure companies and their drivers meet state and federal safety standards as they transport hazardous or radioactive material within South Carolina.

Motor Carrier Compliance (MCC) Unit 

The Motor Carrier Compliance Unit is comprised of STP officers and auditors who travel to commercial trucking companies throughout the state conducting safety audits of their commercial motor vehicle fleets and driver information, all while analyzing company information to ensure compliance with safety regulations designated by Federal Motor Carrier Safety Administration.

DRIVE Team 

The STP DRIVE Team focuses on traffic enforcement, criminal drug interdiction, impaired driving detection and enforcement, and identifying and stopping human trafficking by conducting high visibility enforcement operations in identified “high crash corridors” throughout the state.

Frequently Asked Questions

How do I pay a Uniform Size, Weight, Idling, and Safety Citation? 

Note – these citations begin with the letters WA, which is displayed on the lower right-hand corner of the citation.

To pay a citation for size, weight, and safety violations, visit the State Transport Police's Uniform Size, Weight, Idling, and Safety Online Citation Payment portal here.   

How do I pay a Uniform Traffic Ticket? 

To pay a Uniform Traffic Ticket, you must make a payment to the city or county in which the ticket was issued. You can learn more about the process, step-by-step at the South Carolina Court Payments webpage here.

Uniform Traffic Ticket Search (Example: I lost my ticket and need the ticket number)

Note – these citations begin with the numbers 2025.

If you need to identify your ticket number, visit the South Carolina Judicial Branch's Traffic Ticket Search webpage here. 

How do I find out where load restricted bridges are located in South Carolina?

You can view all load restricted bridges in the state on the SC Department of Transportation's interactive map here. 

Become an STP Officer 

Do you want to join a proud history and enjoy an exciting future? Consider a career with the State Transport Police! 

Find out more about STP career opportunities here.