MontanaOversize & overweight permits.

A superload permit is required when the load:

• Is over 18′ wide
• Is over 17′ high
• Is over 150′ long
• Needs Bridge Bureau approval because of its weight, truck configuration or route

MDT's decision times and approval periods by superload class:

• Class 1 (over 18′–34′ wide, 17′–24′ high or 150′–200′ long): two working days
• Class 2 (over 34′ wide, 24′ high or 200′ long): five working days
• Class 3 (weight needs Bridge Bureau approval, within 18′ W, 17′ H, 150′ L): normal rules set hours and restrictions
• Class 1 and 2 approvals are good for 60 days; Class 3 for one year

Documents MDT requires with a superload application:

• Over 18′ to 20′ wide: contact list, configuration and insurance certificate; traffic control plan and route survey case by case
• Over 20′ wide: adds traffic control plan, route survey, load supervisor's phone and a breakdown contingency plan
• Over 150′ long: traffic control plan, route survey, load supervisor's phone and insurance certificate
• Over 17′ high: also a utility worksheet and telephone letters
• Trunnion or dolly setups (eight or more tires across): a trunnion axle spacing diagram

MDT may set conditions on a superload permit, and the superload instructions add two fixed steps:

• May require: approval from local governments and affected utilities
• May require: all other necessary permits and the insurance required by ARM 18.8.801
• May require: a travel plan and/or route survey
• May require: travel only on set days or hours, and none in bad weather
• May require: enough traffic control personnel, equipment and devices
• Always: notify the railroads before the move if the route crosses tracks
• Always: the contact list includes city, county and tribal contacts on non-Interstate routes

An MDT permit may not cover county roads or city streets; a county or city permit may also be required.

Class 1 and Class 2 superload permits carry restriction 41: before travel, notify local law enforcement, fire and ambulance services in each jurisdiction of the move's route, time and date. MDT publishes no fixed law enforcement escort threshold.

Over 17′ high, the front pilot car carries a height pole or other device that detects overhead clearance.

• Over 24′ high: add a rear pilot car

On Interstates, width pilot cars run behind the load:

• Over 16′6″ to 18′ wide: 1 rear pilot car
• Over 18′ wide: at least 2 rear pilot cars side by side

A passenger car or two-axle truck at least 60″ wide (GVWR 14,000 lb or less; service trucks up to 26,001 lb), with:

• OVERSIZE LOAD sign visible from front and rear, 8″+ black letters on yellow; remove it when not piloting
• Flashing amber lights (at least 5″ across, 50 candlepower, 60–90 flashes a minute) at each end of the sign, visible 360°; a revolving or strobe light may substitute
• Two-way communication
• Stay within 1,000′ of the permitted load
• Current registration and valid insurance

When a move needs pilot cars, do not hold up traffic for more than 15 minutes.

Heavy loads get bridge conditions that add pilot cars on non-Interstate routes:

• Regular: no added pilot cars
• 10 mph condition: 1 rear pilot car
• Bridge centerline (BCL): 1 front and 1 rear pilot car
• Very heavy loads: the Bridge Bureau may set Interstate speed limits that need pilot cars, extra signs and a traffic control plan

Carry a legible printed or electronic copy of the permit in the assigned vehicle.

• A permit marked "page 1 of ?" is not valid without all its pages and attachments
• False information can bring permit confiscation, citations or fines, or suspension of permit privileges

Writing on the permit voids it. Only the permittee's signature is allowed; only MCS staff can amend a permit.

A trip permit runs long enough to complete the move and is void once the vehicle leaves the state.

Oversize permits need at least $1,000,000 combined single limit bodily injury and property damage liability per occurrence. Permits are issued to power units only.

For a GVW fee permit at 55,000 lb or more, a current IRS Form 2290 (HVUT) must be submitted before the permit is finalized.

MCS checks your FMCSA registration when an account is set up and as needed. Mismatches with the federal record slow down MCS processing.

Term over-dimensional permits run for the calendar year:

• 95′ long, 15′ wide, 15′6″ high: $75
• Mobile or manufactured home, 16′ wide and 110′ long: $75
• 120′ non-divisible length (length only): $125
• 100′ doubles (Interstate only): $125; triples: $200
• Calendar-year term permits expire December 31 with no grace period

Annual/term permits cover mobile or manufactured homes up to 16′ wide, 110′ long and 15′6″ high.

• Towing units need one or more dual-wheel drive axles and a wheelbase of at least 100″
• An assembled home or modular building may move as one unit on house-moving equipment under a special permit

Allows 10% excess weight on non-Interstate highways from December 1 through March 7.

• $50 for 30 days or $150 for the season
• Can be suspended early if roads thaw
• Not valid with other overweight permits or on posted bridges or roads

Implement dealer permits are not limited by weekend or holiday travel restrictions, but lighting, pilot car and daylight rules still apply by size.