South Carolina OS/OD Overview
Permit Required
Yes – oversize or overweight loads require a permit from the South Carolina Department of Transportation (SCDOT).
Legal Limits (Without Permit)
- Width: 8'6"
- Height: 13'6"
- Length: 75' (combo); 53' trailer allowed
- Weight: 80,000 lbs GVW
Permitted Load Maximums (Typical Upper Limits)
- Width: Up to 16' with escort
- Height: Over 15' requires route survey and utility coordination
- Length: Over 125' with routing review
- Weight: 130,000+ lbs with axle and bridge analysis
Superloads must be submitted well in advance and may require coordination with law enforcement, utility companies, and SCDOT engineers.
Travel Hours
- Standard: Sunrise to Sunset only
- Weekend: No movement after noon Saturday or any time Sunday for most OS/OW loads
- Holidays: No travel on major holidays or after 12:00 PM the day before
- Night travel: Typically not allowed unless permitted for smaller loads with adequate lighting
Escort Requirements (General Guidelines)
| Dimension | Escort Requirement |
|---|---|
| Width > 12' | 1 Escort (rear or front depending on road type) |
| Width > 14' | 2 Escorts (front and rear) |
| Height > 15' | High pole escort and route clearance required |
| Length > 125' | 1 or more escorts depending on configuration and route |
Additional Notes
- All oversize loads must display “Oversize Load” signs, red/orange flags, and amber flashing lights
- Many rural roads and bridges have strict limits – verify routing carefully
- Permits are issued through the SCDOT Oversize/Overweight Permitting System
Detailed Information
PERMITS: Permits are valid for seven days. Must have permit prior to entering the state.
OPERATING TIME: One-half hour after sunrise to one-half hour before sunset, Monday through Saturday. No Sunday travel. Overweight only not over 130,000 pounds gross may have continuous travel if they can maintain traffic flow speed. Over 130,000 pounds may travel Monday through Friday only.
RESTRICTED TRAVEL: No loads over 12' wide up to 15' wide are to be moved over state highways in close proximity to large urban areas between the hours of 7:00 – 9:00 AM and 3:00 – 6:00 PM on school days and 4:30 – 6:00 PM on other days, and loads over 15' wide up to 16' wide must be moved between the hours of 9:00 – 3:00 during school days and 9:00 – 4:00 other days. Routes between I-95 and the Myrtle Beach area are prohibited on Friday and Saturday form Memorial Day through Labor Day. No travel on major holidays and holiday weekends.
LEGAL DIMENSIONS: Width: 8'6" Interstate and designated highways Height: 13'6 Length: 53'0 semitrailer and load (not to exceed 41' from center of kingpin to center of rear tandem). Overhang: 5' rear overhang on a 48' semitrailer, none on a 53' Note: SC will not permit overhang with multiple pieces. They will only permit it with a non-divisible load. Weight: 80,000 Gross Single – 20,000 Tandem – 34,000 Tridem – 35,200 depends on spacings
ROUTINE PERMIT LIMITS: Width: 16' Length: 125' Overhang: 3' front of trailer, 15' rear on 48' to 53' semi-trailer Height: No set limits – determined by route. Must be at least 6" less than any overhead structure. Weight: 5 axles – 90,000 6 axles – 110,000 7 axles – 130,000 Single – 20,000 Tandem – 40,000 Tridem – 60,000 Quad – 80,000 Loads exceeding these dimensions are considered as superloads.
ESCORTS: Width: Over 12' on 2-lane highways – 1 escort; over 14' (all highway) – 2 escorts, over 16' – 2 escorts and 2 police Height: Not specified. Permittee is responsible for vertical clearances. Length: Not specified Overhang: Over 10' rear – 1 escort
EXCEPTIONS & MISCELLANEOUS: Implements of husbandry, including farm tractors, forestry equipment and road machinery, are exempt from needing permits when the load is not over 12' wide, 13'6 high or 90,000 pounds gross. This exemption is for daylight running, and may run seven days a week.
SIGNS, FLAGS & LIGHTS: "Oversize Load" signs are required at front and rear for all loads exceeding 12' wide, and flags are required on each corner. A rotating amber beacon or strobe light is required on rear of loads exceeding 12' wide up to 14' wide. When width is over 14' wide up to 16' wide, a rotating amber beacon or strobe is required on each outer rear corner of the load. For any rear overhang of 4' or more, a red flag must be displayed at the extreme rear of the load, and a rotating amber beacon light or strobe light must be displayed there when traveling from one-half hour after sunset to one-half hour before sunrise, or when windshield wipers must be used or inclement weather or other conditions reduce visibility below 500 feet.