OSOW
(262) 666-2266Go To App

OSOW Marketing

Montana OSOW Regulations

Permit, escort, and operating-hour requirements for oversize and overweight moves in Montana.

Request a Quote Call 24/7: (262) 666-2266

Montana OSOW Regulations (MDT)

  • Width: 8'6"
  • Gross vehicle weight: 80,000 lbs maximum
  • Single axle: 20,000 lbs
  • Tandem axle: 34,000 lbs
  • Tridem axle: 42,000 lbs

Permit Dimensions and Weights

Annual/Term Permits (Valid up to)

  • Width: 16' maximum
  • Height: 15'6" maximum
  • Length: 110' maximum

Routine Permits

  • Width: 18' maximum
  • Height: 17' maximum
  • Length: 150' maximum

Overweight Permits

  • No axle may exceed 5,000 lbs of excess weight
  • Single axle: Cannot exceed 5,000 lbs excess
  • Tandem axle: Cannot exceed 15,000 lbs excess

Permit Validity

  • 3 to 5 days

Escort/Pilot Vehicle Requirements

When Escorts Are Required

Interstate Highways

  • Over 120' long OR 16'6" wide: Escort required

Two-Lane Highways

  • Over 110' long OR 12'6" wide: Escort required
  • Over 12' wide: 1 front escort required
  • Over 14' wide: 1 front escort AND 1 rear escort required
  • Over 105' long: 1 rear escort required

Pilot Vehicle Specifications

Vehicle Requirements

  • Passenger car or two-axle truck:
    • Minimum 60" wide
    • Maximum 14,000 lbs
  • Service or mechanic trucks used as pilot cars/escorts:
    • Maximum 26,001 lbs

Transport Vehicle Requirements

Signs

For vehicles/loads exceeding 10' wide:

  • "OVERSIZE LOAD" signs required front and rear
  • Letters: Minimum 8 inches height
  • Colors: Dark color on light background

Lights

  • 5" flashing amber lights, revolving beacon, or strobe light(s) required
  • Placement: At each end of Oversize Load sign on power unit

Escort Vehicle Signs

  • "OVERSIZE LOAD" or similar wording must be displayed
  • Visible: From front and rear at all times when piloting oversize load
  • Letters: Minimum 8 inches height

Operating Times

Continuous 24/7 Travel Allowed

For loads not exceeding:

  • 110' long
  • 10' wide
  • 15'6" high

Daylight Travel Only

For loads not exceeding:

  • 120' long
  • 18' wide
  • 18' high
  • Hours: 1/2 hour before sunrise to 1/2 hour after sunset
  • Including Saturdays and Sundays
  • Exception: Red Route highways (may have additional restrictions)

Contact Information

  • Website: https://www.mdt.mt.gov/
  • State: Montana
  • Agency: Montana Department of Transportation (MDT)

Regulatory References

  • Montana Department of Transportation
  • Montana Permit Restrictions
  • https://www.mdt.mt.gov/
  • https://jjkellercompliancenetwork.com/regsense/oversize-and-overweight-movements-montana

Last Updated: 2025-11-11