The following information about Idaho Oversize Permits is for informational purposes only. It’s important to always read your permits and provisions sheets carefully as we cannot guarantee the accuracy of the information provided. If you have any questions or need assistance, you can contact the following number.

Idaho DOT #: 208-334-8420

Idaho Oversize Permits Duration

Idaho permits for oversized loads remain valid for a period of five days.

Operating Time

Travel is permitted from half an hour before sunrise to half an hour after sunset, including Saturdays and Sundays for the majority of routes. For loads up to and including 10 feet wide, 110 feet long, or 14 feet 6 inches high, travel is allowed 24/7 on most routes, with lighting as specified on the permit. Weekend travel is permitted during daytime hours on the majority of routes.

Restricted Travel in Idaho

 If the width exceeds 13 feet, travel is restricted between 6:30 am – 8:30 am, 11:30 am – 1:30 pm, and 4:00 pm – 6:00 pm in Boise, Caldwell, Coeur d’Alene, Idaho Falls, Lewiston, Nampa, Pocatello, Twin Falls, Garden City, and Chubbuck. Holiday travel restrictions may vary depending on dimensions.

Legal Dimensions for Idaho Oversize Permits

Length:

  • 53′ semi-trailer on National Network
  • 48′ trailer on non-N.N. (“non-designated”)

Note:

Numerous two-lane highways in Idaho lack designation, such as US-12, except in the Lewiston to Spalding segment, US-93 from Salmon to Challis, and US-95 from Council to Grangeville.

Divisible loads

  • , Trailers surpassing 48 feet are permissible only with an annual additional length permit, and the off-track measurement for tractor-trailers must not exceed 5.50 feet (3.00 feet on select mountain routes).
  • Non-divisible loads are included in either a single or annual permit, irrespective of the off-track measurement.

Overhang:

4′ front, 15′ rear

Width:

8′-6″

Height:

14′

Weight:

80,000 Gross

  • Single – 20,000
  • Tandem – 34,000
  • Tridem – depends on spacings
  •  Steer – 600 pounds per inch of tire tread width (13,200 pounds with 11-inch tires).

Divisible Loads Above 80,000: 

You may surpass 80,000 gross weight on state highways without a permit, provided you adhere to legal axle/group weights and hold a license for at least the amount of your gross weight. However, for any Interstate routes, obtaining an Annual Excess Weight Permit is necessary.

Get Permit Now

Call (832) 454-5883 For Permit Consultation

Routine Permit Limits in Idaho

Length:

110′

Width:

16′

Height:

15′-6″

Weight:

  • Single – 33,000 to 22,000*
  • Tandem – 56,000 to 38,500*
  • Tridem – 70,500 to 48,000*
  • Steer – 600 pounds per inch of tread width (13,200 pounds for 11″ tires)

Maximum group weights vary based on route classification, with Interstate routes having the highest allowances.

Loads exceeding these dimensions or are considered as Super Loads for Idaho Oversize Permits.

Idaho Oversize Permits image

Escort Requirements for Idaho  Oversize Load Permits

On 2-Lane Highways:

Length:

Over 100′ – one escort

Overhang:

Over 25′ rear – one escort.

Width:

  • Over 12′ – one escort
  • over 14′ – two escorts
  • over 16′ – may require three escorts

Height:

Over 16′ – one escort.

On Interstate System:

Length:

Over 120′ – one escort.

Overhang:

Over 25′ rear – one escort.

Width:

  • Over 15′ – one escort
  • Over 16′ – may require two or three escorts

Height:

Over 16′ – one escort.

Miscellaneous

If exceeding legal axle weights, all lift axles must be in contact with the ground. Blades, buckets, etc., can be removed and transported on the same load, contingent upon the route and circumstances, with the state making determinations on a case-by-case basis.

Signs, Flags & Lights for Idaho Oversize Load Permits

The Idaho Oversize permits outlines the specific requirements. “Oversize Load” signs must be displayed on all loads exceeding the width limit. Flags are mandatory on all four corners and extremities of loads surpassing the width limit, as well as on the rear overhang if it exceeds 4 feet. Loads that are overweight only do not necessitate the use of signs or flags.