Montana permits
Montana Oversize Permit Rules
Legal limits, pilot vehicles, height poles, travel hours, weekends, holidays and superloads for oversize and overweight loads in Montana, each checked against the MDT permit restrictions and the Montana rules.
Last checked: Oct 15, 2026
This page is general information only, not legal advice and not a permit. Rules change often and each state's permit and official rules are the final word. Always confirm limits, escorts, routes and travel times with the state permit office before moving a load. Reliable Transport LLC is not responsible for decisions made using this information.
- Pilot cars start
- Over 12'6"W
- Height pole
- Over 17'H
- Legal size
- 8'6"W, 14'H
Hauling through other states? Use our permit map and route planner
Open the route plannerMDT permits
How Montana sizes up a heavy load
The Montana Department of Transportation (MDT) issues oversize and overweight permits through its Motor Carrier Services division, under MCA Title 61, Chapter 10 and the MDT rules in ARM Title 18, Chapter 8. These are the numbers we plan every Montana load with. Run your exact load and route through our permit tool to see every state on the trip.
Check your load
Enter your width, height, length and weight in our permit tool to see the rules for every state on your route, each with its official source.
Montana limits
Montana legal limits and permit thresholds
Over any legal limit, the load needs an MDT permit before it moves.
Montana legal size, weight and permits
Official sources linked| Rule | Limit |
|---|---|
| Legal width | 8'6"W (MDT permitting reference and FAQs, MCA 61-10-102) |
| Legal height | 14'H (MDT permitting reference and FAQs, MCA 61-10-103) |
| Superload permit | Over 18'W, 17'H or 150'L, or when the MDT Bridge Bureau must review the weight or configuration (ARM 18.8.509, MDT permitting reference and FAQs) |
| Superload class 1 | Over 18'W up to 34'W, over 17'H up to 24'H, or over 150'L up to 200'L: MDT decides within two working days of a complete application (MDT Montana Permit Restrictions, ARM 18.8.509) |
| Superload class 2 | Over 34'W, 24'H or 200'L: MDT decides within five working days of a complete application (MDT Montana Permit Restrictions, ARM 18.8.509) |
Escorts
Montana escort requirements
Montana sets pilot vehicles by width, height and length, and the counts differ on and off the interstate.
Montana escorts by load size
Official sources linked| Load | Escorts |
|---|---|
| Over 12'6"W, off the interstate | One front pilot vehicle (MDT Montana Permit Restrictions, ARM 18.8.511A) |
| Over 16'6"W, off the interstate | One front and one rear (MDT Montana Permit Restrictions, ARM 18.8.511A) |
| Over 18'W, off the interstate | At least two front and one rear (MDT Montana Permit Restrictions, ARM 18.8.511A) |
| Over 24'W, off the interstate | At least two front and two rear (MDT Montana Permit Restrictions, ARM 18.8.511A) |
| Over 16'6"W, interstate | One rear pilot vehicle (MDT Montana Permit Restrictions, ARM 18.8.511A) |
| Over 18'W, interstate | At least two rear pilot vehicles, side by side (MDT Montana Permit Restrictions, ARM 18.8.511A) |
| Over 150'L, off the interstate | One rear pilot vehicle (MDT Montana Permit Restrictions, ARM 18.8.511A) |
| Over 200'L, off the interstate | One front and one rear (MDT Montana Permit Restrictions, ARM 18.8.511A) |
| Over 17'H | One front pilot vehicle with a height pole; over 24'H, one rear pilot vehicle as well (MDT Montana Permit Restrictions, ARM 18.8.511A) |
Pilot vehicle rules come from ARM 18.8.511A and MDT permit restrictions 36a to 37f. The rule also has separate wording for loads from 120'L to 150'L that does not match the MDT restriction, so that range is left to the permit. (MDT Montana Permit Restrictions, ARM 18.8.511A)
Height and routes
Route surveys, tall loads and utilities
What Montana asks of the tallest loads.
Height pole
Over 17'H, the front pilot vehicle carries a height pole or an equivalent device; over 24'H, a rear pilot vehicle runs as well. (MDT Montana Permit Restrictions, ARM 18.8.511A)
Tall load travel
Off the interstate, loads over 15'6"H travel in daylight only and not on holidays or holiday weekends, and loads over 17'H do not travel on weekends. (MDT Montana Permit Restrictions, ARM 18.8.509)
Superload review
Over 17'H the move is a superload, and MDT may require a travel plan or route survey and approval from affected utilities. (ARM 18.8.509, MDT superload instructions)
Travel times
Travel hours, nights, weekends and holidays
When a permitted load may move in Montana.
Interstates
Permitted loads up to 18'W may travel 24 hours a day, 7 days a week, including holidays and holiday weekends. (MDT Montana Permit Restrictions, ARM 18.8.509)
Off the interstate
Loads up to 10'W, 150'L and 15'6"H may travel 24 hours a day; bigger loads travel in daylight only. (MDT Montana Permit Restrictions, ARM 18.8.509)
Weekends
Off the interstate, loads over 18'W, 150'L or 17'H do not travel on weekends. (MDT Montana Permit Restrictions, MDT permitting reference and FAQs)
Holidays
Loads over 18'W on interstates, or over 12'6"W, 150'L or 15'6"H off the interstate, do not travel on New Year's Day, Memorial Day, Fourth of July, Labor Day, Thanksgiving or Christmas, or over the holiday weekend. Over Thanksgiving, the stop runs Thursday through Sunday. (MDT Montana Permit Restrictions, ARM 18.8.101)
Road conditions
No travel when MDT has placed the route under severe driving conditions. (MDT Montana Permit Restrictions, ARM 18.8.509)
Superloads
Montana superloads
Over 18'W, 17'H or 150'L, or when the MDT Bridge Bureau must review the weight or configuration, a Montana load needs a superload permit approved by the MDT district administrator. Class 1 superloads, up to 34'W, 24'H or 200'L, get a decision within two working days of a complete application; class 2 superloads, bigger than that, within five working days. MDT may also require a travel plan or route survey, utility approvals, set travel days and hours, and traffic control. (ARM 18.8.509, MDT Montana Permit Restrictions, MDT superload instructions)
See how we plan the biggest loads on our Superload Transport page.
Our moves
Heavy loads we have moved
CAT 775F off highway truck
A CAT 775F haul truck from Tennessee to California, at 187,000 lbs loaded.
Read the move →207,000 lb dryer drum
A 207,000 lb dryer drum from Louisville, KY to Richmond, VA.
Read the move →150,000 lb transformer
A 150,000 lb transformer from Pocatello, ID to Akron, OH.
Read the move →Moving a load in Montana?
Send the dimensions and weight. We file the Montana permit and book the escorts.
Request a quote →See every move on our Moves page.
Sources
Official Montana sources
Every rule on this page is taken from the official rule text below and confirmed by a second source. Rules we could not confirm twice are left off this page. Rules change, and the permit itself always decides. Last checked: Oct 15, 2026.
Questions
Montana permit questions
What are the legal size limits in Montana?
8'6"W and 14'H.
When does Montana require pilot vehicles?
Off the interstate, one front pilot vehicle over 12'6"W, front and rear over 16'6"W, and more over 18'W. On interstates, one rear pilot vehicle over 16'6"W and two side by side over 18'W.
Can oversize loads move at night in Montana?
On interstates, permitted loads up to 18'W may travel 24 hours a day. Off the interstate, loads over 10'W, 150'L or 15'6"H travel in daylight only.
Which holidays stop oversize loads in Montana?
New Year's Day, Memorial Day, Fourth of July, Labor Day, Thanksgiving and Christmas, plus the holiday weekend. The stop covers loads over 18'W on interstates and loads over 12'6"W, 150'L or 15'6"H off the interstate.
When is a Montana load a superload?
Over 18'W, 17'H or 150'L, or when the MDT Bridge Bureau must review the weight or configuration.
Keep planning
More for your Montana move
Permit rules in other states
Hauling through other states? Use our permit map and route planner
Open the route plannerReliable Transport LLC | Reliable Heavy Haul
Ready to move it?
We haul oversize and overweight loads across the USA and Canada from our home base at 7660 W Third St, Dayton, OH 45417. Send your load details and we will plan the Montana permit, route and escorts.
This page is general information only, not legal advice and not a permit. Rules change often and each state's permit and official rules are the final word. Always confirm limits, escorts, routes and travel times with the state permit office before moving a load. Reliable Transport LLC is not responsible for decisions made using this information.