---
title: South Carolina Oversize & Overweight Permits (OS/OW) | SCDOT Superload | Alpine Truck Service
description: Expedited South Carolina SCDOT oversize permits, Port of Charleston routing, Columbia curfews, and SCHP escorts across I-85, I-26, and I-95. Call (918) 607-6547.
image: https://www.alpinetruckservice.com/alpine-third-party-charges.webp
---

# South Carolina Oversize, Overweight & Superload Permitting Services

Comprehensive commercial trucking permits and heavy haul compliance across South Carolina.

## Agency & Permitting Authority
- **Agency**: South Carolina Department of Transportation (SCDOT)
- **Portal**: SCDOT OS/OW Permitting Office
- **Regulatory Advisory**: State DOT regulations and permit processing queues are determined by individual state transportation authorities and vary by agency workload. Carriers should verify active route advisories and state requirements prior to movement.

## Legal vs. Routine Permitted Dimensions
- **Legal Width**: 8' 6" | **Max Routine**: 16' 0"
- **Legal Height**: 13' 6" | **Max Routine**: 15' 6"
- **Legal Length**: 53' Semi-Trailer / 65' Overall | **Max Routine**: 125' 0"
- **Legal Gross Weight**: 80,000 lbs | **Max Routine**: 150,000 lbs
- **Axle Limits**: Single: 20,000 lbs, Tandem: 34,000 lbs (35,200 with 5% statutory tolerance on state routes), Tridem: 42,000 lbs

## Permitting Scope & Services in South Carolina
- **Routine Oversize (OS) Cab-Cards**: Single-trip authorizations for dimensions exceeding 8' 6" width or 13' 6" height.
- **Overweight (OW) Axle Permits**: Overload cab-cards for heavy machinery and configurations exceeding 80,000 lbs GVW.
- **Multi-Axle Superload Permits**: Specialized filings exceeding Over 150,000, including State DOT and certified partner bridge reviews, route surveys, and police escorts.
- **Annual & Blanket Fleet Permits**: Continuous-operation annual highway authorizations for construction fleets.
- **Temporary Trip & Fuel Permits**: 72-hour IRP vehicle registration and IFTA fuel tax credentials.
- **County, City & Toll Road Clearances**: Municipal authorizations and turnpike clearances.

## Superload Permitting & State Review Protocol
- **Weight Trigger**: Over 150,000 lbs GVW or exceeding SCDOT Bridge Structural Formulas
- **Width Trigger**: Over 16' 0" wide
- **Height Trigger**: Over 15' 6" high
- **Length Trigger**: Over 125' 0" overall length
- **State & Partner Bridge Review**: South Carolina Department of Transportation (SCDOT) electronic systems and certified structural engineering partners evaluate axle load distribution across bridge structures upon submission.
- **Route Surveys & Clearances**: Required for extreme heights/widths to verify overhead physical clearances.
- **Utility & Escorts**: Coordinated wire lifts with power utilities and State Police / Highway Patrol escorts.

## Pilot Cars & Escort Vehicle Requirements
- **Front Escort**: Required over 12' 0" wide on two-lane roads; over 14' 0" wide on multi-lane highways
- **Rear Escort**: Required over 14' 0" wide on multi-lane highways; length exceeding 90' 0"; rear overhang > 15' 0"
- **Height Pole**: Required for loads exceeding 15' 0" in height (lead vehicle with calibrated pole)
- **Police Escort**: South Carolina Highway Patrol (SCHP) escort required over 16' 0" wide, 16' 0" high, or gross weight over 150,000 lbs

## Metro Curfews & Travel Restrictions
- **Curfew Zones**:
  - Columbia Metro (I-26, I-20, I-77, I-126): 7:00–9:00 AM & 4:00–6:00 PM M-F
  - Charleston Metro (I-26, I-526, US-17, Ravenel Bridge): 7:00–9:00 AM & 4:00–6:00 PM M-F
  - Greenville-Spartanburg (I-85, I-385): 7:00–9:00 AM & 4:00–6:00 PM M-F
- **Travel Rules**: Daylight only (1/2 hour before sunrise to 1/2 hour after sunset) Monday through Saturday. Sunday travel allowed until 12:00 noon for loads under 12' wide. Overweight-only continuous travel allowed with lighting.

## Key Freight Corridors
- I-85 (Upstate Industrial Spine)
- I-26 (Columbia to Port of Charleston)
- I-95 (Atlantic Seaboard Arterial)
- I-77 (Columbia to Charlotte)
- I-20 (Columbia to Augusta)
- US-17 (Coastal Freight Corridor)

## Frequently Asked Questions
### How fast does SCDOT issue a South Carolina oversize permit?
SCDOT processes routine single-trip permits typically within 2–4 business hours. Superloads requiring bridge structural reviews take 3–5 business days.

### What are South Carolina pilot car escort rules?
South Carolina requires 1 escort for loads over 12' wide on 2-lane roads and over 14' wide on multi-lane highways. Loads over 90' long require a rear escort. Height over 15' requires a height pole.

### What are the Charleston and Columbia rush hour curfews?
Oversize vehicles cannot travel on Charleston (I-26/I-526) or Columbia (I-26/I-20/I-77) expressways between 7:00–9:00 AM and 4:00–6:00 PM on weekdays.

### What is South Carolina's superload threshold?
Shipments over 150,000 lbs gross weight, 16' wide, 15'6" high, or 125' long are classified as superloads, requiring SCDOT bridge analysis and Highway Patrol escorts.

## Contact & Direct Dispatch
- **Direct Phone**: (918) 607-6547 (CALL: [918-607-6547](tel:9186076547))
- **Email**: [permits@alpinetruck.com](mailto:permits@alpinetruck.com)
- **Online Intake**: [alpinetruckservice.com/permits/south-carolina](https://www.alpinetruckservice.com/permits/south-carolina)