Tennessee OS/OD Overview
Permit Required
Yes – all oversize or overweight loads require a permit from the Tennessee Department of Transportation (TDOT), Overweight & Overdimensional Permits Office.
Legal Limits (Without Permit)
- Width: 8'6"
- Height: 13'6"
- Length: 75' (combo); 53' trailer allowed
- Weight: 80,000 lbs GVW (with legal axle spacings)
Permitted Load Maximums (Typical Upper Limits)
- Width: Up to 16' with escorts
- Height: Over 15'6" requires a route survey and utility clearance
- Length: Over 120' requires routing review and escort(s)
- Weight: Over 200,000 lbs with detailed axle spacing and bridge review
Superloads require pre-approval and often additional routing time for structural and traffic engineering review.
Travel Hours
- Standard: Sunrise to Sunset only
- Weekend: No movement after 12:00 PM Saturday or any time Sunday
- Holidays: No movement on major holidays or after noon the preceding business day
- Night travel: May be allowed under specific conditions for loads under 10' wide and 100' long with proper lighting
Escort Requirements (General Guidelines)
| Dimension | Escort Requirement |
|---|---|
| Width > 12' | 1 Escort (rear on 4-lane, front on 2-lane roads) |
| Width > 14' | 2 Escorts (front and rear) |
| Height > 15'6" | High pole escort and utility coordination |
| Length > 120' | 1 or more escorts as determined by route and configuration |
Additional Notes
- Loads must display “Oversize Load” signs, red/orange flags, and amber lights as required by permit
- Mountain routes and urban areas may have additional restrictions or curfews
- Permits are issued through the TDOT ePermits System
Detailed Information
PERMITS: Permits valid for ten days. Must have permit prior to entering state.
OPERATING TIME: Daylight only (one-half hour before sunrise to one-half hour after sunset) Monday through Saturday. No travel on Sundays. 24/7 movement allowed if less than 16’ wide, 15’6” high, 120’ long or 165,000 lbs. Restricted Travel: Movements over 12'6" in width or 85' long or greater or will not be allowed within any statewide city limits and all heavily traveled adjoining commercial or residential areas between the hours of 7:00 9:00 AM and 4:00-6:00 PM from Monday through Friday. No travel on major holidays.
LEGAL DIMENSIONS: Width: 8'6" Height: 13' 6" Length: Not to exceed 50' from kingpin to end of trailer or load is legal length. poles when overall length is 75feet or more. Overhang: See Length, above. Weight: 80,000 Gross Single – 20,000 Tandem – 34,000 A permit is required for utility Tridem – 42,000 w/ 8' of spacing, 42,500 w/ 9' spacing
ROUTINE PERMIT LIMITS: Width: 16' Height: 15' Length: 120' Weight: 5 axles – 100,000 6 axles – 120,000 7 axles - 140,000 8 axles – 160,000 Single – 20,000 Tandem – 46,000 Tridem – 60,000 Quad - 80,000 Loads exceeding these dimensions are Super Loads. Generally, movements of over 16' wide or 15' high will not be permitted unless it can be proven that the movement is in the interests of public welfare, safety, or national defense. Movements over 16' high will not usually be permitted, and would require a letter of necessity describing the load and why it needed to go through TN to possibly get a permit.
ESCORTS: Width: On Interstate and 4-lane highways: Over 12'6" – 1 escort, over 14' – 2 escorts. On 2-lane highways: Over 10' – 1 escort (unless over 24' pavement width excluding shoulders), over 14' – 2 escorts. Height: Over 15' (if approved) – 1 escort with height pole Length: Over 85' – 1 escort, over 120' – 2 escorts. (Over 75' to 85' long requires rotating or strobe type amber light).
MISCELLANEOUS: Bulldozer blades or loads with protruding sharp objects shall be loaded with the blade or protruding sharp object to the rear of the hauling equipment when the blade exceeds 10'6” in width. No permits will be issued for blades or protruding sharp objects creating width in excess of 13'6". Combination loads cannot be permitted for two overdimensions on two different pieces (example: cannot permit for a load with overwidth dozer and overheight backhoe on same load).
SIGNS, FLAGS & LIGHTS: All movements exceeding 10' in width and/or 75' in length require “Oversize Load” at front and rear. Loads over 75’ overall length but not exceeding 85’ require a rotating or strobe type amber light on the end of the load. Red flags are required on overwidth loads front and rear, and top and bottom each side where load is widest (or at the widest point if it is between the top and bottom). Red flags must be placed at the extreme rear end of overlength loads or when there is over 4' rear overhang. No sign or flag requirements are listed for overheight only loads. For overweight-only loads, you still need Oversize Load signs according to a scale officer, but the rules and regulations do not specify this.
*Kingpin is measured from kingpin to end of trailer or load. If over 50’ kingpin, you will only get 40,000 lbs on drives *