South Carolina commercial vehicle weight limits follow the federal Interstate standard of 80,000 lbs gross, 20,000 lbs per single axle, and 34,000 lbs per tandem axle group. The federal bridge formula (23 U.S.C. 127) applies on all routes. No seasonal weight restrictions on Interstate highways. Oversize and overweight permits are available from SC DOT for loads exceeding standard limits. Verify current road-specific postings with the South Carolina DOT before routing heavy loads.
The federal bridge formula limits the weight on any group of axles based on the distance between the outermost axles in the group. It applies in South Carolina on all routes where federal standards apply.
W = maximum weight in lbs · L = axle spacing in feet · N = number of axles
South Carolina DOT issues oversize/overweight permits through the SCDOT Permits Office. Single-trip permits required for loads exceeding standard weight or size limits. Annual permits available for qualifying recurring heavy operations. Superloads require route engineering review and may require law enforcement escort.
Apply for South Carolina OS/OW Permit →The maximum gross vehicle weight in South Carolina is 80,000 lbs on Interstate highways, matching the federal standard. Single axle limit is 20,000 lbs and tandem axle is 34,000 lbs. State routes and secondary roads may have lower posted limits. Overweight permits from SCDOT are required for loads exceeding these limits.
No. South Carolina does not impose seasonal spring weight restrictions on Interstate highways or major state routes. The state's mild coastal and Piedmont climate means roads are generally not subject to the freeze-thaw cycles that cause spring restrictions in northern states. However, secondary roads and county routes may have lower year-round posted limits.
South Carolina oversize/overweight permits are issued by the SCDOT Permits Office. Apply online at scdot.org. Single-trip permits are required for loads exceeding standard weight or dimension limits. Annual permits are available for qualifying recurring heavy operations such as port drayage and industrial logistics.
Container chassis weights at the Port of Charleston must comply with standard South Carolina and federal weight limits (80,000 lbs GVW on Interstates). The I-26 and US-17 corridors serving the port are generally adequate for standard fully loaded containers. Overweight containers require a SCDOT overweight permit before moving off port property.
South Carolina secondary and rural roads often have posted weight limits well below the Interstate standard. Always observe posted signs on state routes and county roads. Timber and agricultural areas in rural South Carolina can have particularly low weight postings on bridges. Contact SCDOT for route-specific weight limit information before dispatching heavy loads on non-Interstate routes.
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Disclaimer
The information on this page is compiled from publicly available government sources and is provided for general informational purposes only. TruckRadar is an independent search engine — we are not affiliated with any government agency and this content does not constitute legal or compliance advice. Regulations change frequently; always verify current requirements directly with the official source before making compliance decisions.
Official source: South Carolina SC Department of TransportationLast reviewed: 2026-04