Montana State Regulations
Transportation Restrictions
The holidays are New Year’s Day, Memorial Day, 4th of July, Labor Day, Thanksgiving Day, and Christmas Day.
Vehicles combinations exceeding 10’ wide (11’ 6” for commercial hay grinders), 110’ long, and over 14’ 6” high are not allowed to travel on holidays or holiday weekends.
If the holiday is on Friday or Saturday there is no travel on Friday, Saturday and Sunday. If the holiday falls on Sunday or Monday there is no travel on Saturday, Sunday and Monday. If the holiday falls on a Tuesday, Wednesday or Thursday, travel is not allowed on that day only, and travel will be allowed on the days preceding and following the holiday. (exception: Implements of Husbandry may not be restricted).
On Red Route Highways, single units over 55’ long, vehicles combinations exceeding 10’ wide, combinations over 110’ long and over 14’ 6” high may not travel after 3:00 PM on Friday to sunrise on Saturday and from noon on Sunday to sunrise on Monday. Vehicle combinations exceeding 18’ wide, 120’ long, or 18’ high may not travel after 3:00 PM on Friday until sunrise on Monday.
Class 1 superloads may be moved only during daylight hours, Monday through Friday. No travel is allowed on holidays or holiday weekends. No travel is allowed after 3 PM on Friday until sunrise on Monday on routes indicated on “red route restrictions” map.
Class 2 superloads may be moved only during daylight hours, from sunrise on Monday until 3:00 PM on Friday.
Extreme caution shall be exercised in the operation of a vehicle when hazardous conditions such as those caused by snow, ice, sleet, fog, mist, rain, dust, smoke, areas of maintenance and construction or any other condition which adversely affect visibility, traction, or the safety of the traveling public. Speed shall be reduced when such conditions exist. When conditions become sufficiently dangerous, the company or operator shall discontinue operations until the vehicle can be safely operated. No travel is allowed when a route has been placed under emergency travel conditions as determined by the Department of Transportation.
Operating Time
Weekend Travel
See Operating Time
Transportation Requirements
Superloads
Anything above Routine Issue dimensions require special approval from the DOT.
Oversize Load Signs
“Oversize Load” signs required for loads exceeding 10’ wide.
Flags/Lights
Flags required when the load exceeds 12’6” wide (16’6” on interstate) and 110’ long (120’ on interstate).
Two flashing amber lights required at the end of the wide load sign. Lights must be operating at all times when moving an oversize load.
Blades
Dozer blade Ok for oversize / overweight as long as the blade doesn’t exceed the width of the
load.
Legal Limits
| Component | Restriction |
|---|---|
| Single Axle | 20,000 lbs. |
| Tandem Group | 34,000 lbs. |
| Tridem Goup | 42,000 lbs. |
| Gross Weight | 80,000 lbs. |
| Width | 8’6″ |
| Height | 14′ |
| Length – Semi-Trailer | 53′ |
| Length | 75′ |
| Overhang | 3’ Front | 4’ Rear |
Routine Issues
| Component | Restriction |
|---|---|
| Width | 18′ |
| Height | 17′ |
| Length | 150′ |
| Axle Weights | Determined on a Case-by-Case basis |
Escort Requirements
| Dimension | Requirement |
|---|---|
| Width 10′-12’6″ | 2 (Front & Rear)* |
| Width Over 12’6″ | 1 Front** |
| Width Over 16’6″ | 2 (Front & Rear) |
| Length 110′ | 1 Rear |
| Superload | 3 (1 Front & 2 Rear) On Interstates, 4 (2 Front & 2 Rear) On Non-Interstate |
| Superload – Length Only | 2 (Front & Rear) On Interstate |
*Escorts required if load is not equipped with lights and signs as required by law
**Rear escort also required if not equipped with lights and signs as required by law