Current Status
Seasonal road restrictions are lifted.
Effective APRIL 16, 2026
All load limits have been revised. The standard rule is a maximum of 350–400 pounds per inch of tire width, depending on the specific road. These temporary restrictions help prevent damage to county roads during the vulnerable spring period.
Overweight Permit
If you need allowance to haul a heavier load on a restricted load, apply for an Overweight Permit.
Quick Summary of Current Limits
- Primary weight limit: 350–400 lbs per inch of tire width (exact limit varies by road—see the table below)
- Restrictions apply only to designated county roads; most roads remain open with no limits
- Heavy commercial vehicles, trucks, and equipment must comply
- Always watch for posted signs at road entrances
- Restrictions are temporary and will be lifted when road conditions improve
- Violations may result in fines and liability for road damage
Affected Roads
Effective April 16, 2026, all season weight restrictions are lifted.
All listed roads have a weight limit of 350 lbs per inch of tire width (single axle maximum 7 tons / 14,000 lbs; tandem axle maximum 14 tons / 28,000 lbs). A 35 mph speed limit also applies unless otherwise posted. Some roads may be signed for the higher 400 lbs per inch limit—always obey posted signs.
Why Seasonal Road Restrictions Exist
In Montana’s rural areas, including Flathead County, roads go through intense freeze-thaw cycles every spring. As temperatures rise, frost deep in the ground melts, leaving the soil underneath wet and spongy. Heavy vehicles can push the road surface down, creating ruts, cracks, and permanent damage. These temporary load limits (often called frost laws) protect the investment in our roads and keep them safe for everyone.
How Weight Limits Work
The limit is measured in pounds per inch of tire width. It tells you the maximum weight your tires can place on the road for each inch of tire tread that touches the ground.
Simple example: If your tire is 10 inches wide and the limit is 350 lbs per inch, your tire can safely carry up to 3,500 lbs (10 × 350). Wider tires spread the weight over more inches, so they can handle a bit more under the same limit. This system is easy to check and protects the road without weighing every axle on the spot.
When Restrictions Are Typically Implemented
Seasonal road restrictions usually begin in late winter or early spring—whenever frost starts leaving the ground—and last until roads firm up, typically by late spring or early summer. Timing varies each year based on weather and is not tied to a fixed calendar date. The Roads & Bridges Department monitors conditions closely and posts updates here.
What Vehicles Are Affected
These limits mainly apply to heavy commercial trucks, semi-trailers, construction equipment, farm machinery, and any vehicle exceeding the posted weight per inch of tire width. Standard passenger cars, light pickup trucks, and most personal vehicles are not affected. If you are hauling a heavy load or driving a commercial vehicle, check the table above and your tire width before traveling restricted roads.
Frequently Asked Questions
Check the Affected Roads table above or look for official signs posted at the road entrance. You can also call the Roads & Bridges Department for the latest status.
Yes—emergency vehicles, law enforcement, and certain essential services are typically exempt. Contact the Roads & Bridges Department in advance if you need a special permit or clarification.
Restrictions stay in place until road conditions improve, usually several weeks. This page is updated as soon as changes occur.
Violations can result in fines and potential liability for any road damage. Always plan your route using the table above when carrying heavy loads.
This page covers only Flathead County roads. For Montana state highways, visit the Montana Department of Transportation (MDT) website. Other counties maintain their own restriction lists.
Contact Info
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