OS/OW Regulations and Permit Compliance Guide
TL;DR Summary
Oversize/overweight (OS/OW) regulations govern the movement of loads exceeding standard legal limits. Each US state and Canadian province has unique requirements for permits, escorts, travel times, and route restrictions. Professional route intelligence platforms like RoadScope help navigate this complexity.
Understanding OS/OW Transportation
Oversize/overweight transportation involves moving loads that exceed standard legal dimensions or weights. These movements require special permits and often involve additional requirements like pilot cars, route surveys, and time-of-day restrictions.
Oversize vs Overweight
Oversize loads exceed legal dimensions: width, height, or length. Overweight loads exceed legal weight limits for axles or gross vehicle weight. Many loads are both oversize AND overweight.
Federal Baseline (United States)
Federal limits on the Interstate Highway System:
- Width: 8'6" (102 inches) for most freight
- Height: No federal limit (typically 13'6" - 14' is practical)
- Length: No overall limit; 48' trailer minimum, 53' common
- Single Axle: 20,000 lbs
- Tandem Axle: 34,000 lbs
- Gross Vehicle Weight: 80,000 lbs
States may have more restrictive limits on state routes.
State Permit Requirements
Each state administers its own permit program with varying:
- Permit types - Single trip, annual, project-specific
- Fee structures - Based on dimensions, weight, miles traveled
- Route restrictions - Specific road exclusions or approvals
- Escort requirements - Based on load dimensions
- Travel time restrictions - Daylight only, no weekends, etc.
- Bridge restrictions - Weight ratings and clearance reviews
Canadian Regulations
Canadian provinces have similar but distinct requirements:
- Provincial permits required for each jurisdiction
- Different dimensional and weight limits than US
- Harmonized regulations in some Western provinces
- Specific requirements for border crossings
Common Permit Categories
Single Trip Permits
One-time permits for specific loads on specific routes. Most common for extremely oversized or overweight loads.
Annual Permits
Blanket permits for multiple movements within size/weight thresholds. Efficient for carriers with regular OS/OW operations.
Super Load Permits
Special permits for loads exceeding typical OS/OW thresholds. Often require engineering reviews and route surveys.
Route Survey Requirements
Many jurisdictions require documented route surveys for large loads:
- Bridge clearance verification
- Overhead obstruction identification
- Turn analysis for intersections
- Weight restriction documentation
- Photo documentation of constraints
RoadScope provides the tools to conduct and document professional route surveys that meet permit requirements.
Compliance Best Practices
- Obtain permits before beginning any OS/OW movement
- Keep permit documentation with the load at all times
- Follow all route restrictions and conditions
- Use qualified pilot cars when required
- Document any deviations or issues
- Maintain compliance records for audits
How RoadScope Helps
RoadScope's OS/OW Regulations Module provides:
- Multi-jurisdiction regulation database
- Permit requirement lookups by state/province
- Weight and dimension limit references
- AI-powered compliance summaries
- Regular updates for regulatory changes
Learn more at https://roadscope.app/features