Montana Truck Weight Limits and Permit Sources

At-a-glance summary

Field-level reference data

Montana’s weight review has a specific fine statute — Montana Code Annotated section 61-10-145 — and a confirmed enforcement structure through Montana Department of Transportation Motor Carrier Services Enforcement. MDT Motor Carrier Services handles permits. Montana’s rural Interstate corridors and long-haul profile mean the federal baseline sees frequent use, but state permit and enforcement materials still matter for any off-Interstate movement.

Reading the Montana weight table

Weight rows use the federal Interstate baseline and the FHWA state law compilation for Montana. Montana’s I-90 and I-15 corridors carry significant long-haul freight. Federal baseline applies on those routes. For US highways, state routes, and local access roads — including routes serving agricultural and energy extraction operations — verify the FHWA state law compilation and any permit conditions.

Montana’s rural character means some routes involve roads with limited infrastructure that may carry lower effective limits than the state baseline. Current bridge and road postings for specific rural segments are worth checking when the move departs from main highway routes.

Permit and route authority in Montana

MDT Motor Carrier Services Permits handles over-limit permits for Montana. Applications go through MDT’s permit system. Montana’s oversize and overweight permit process serves a significant share of agricultural and energy extraction loads. Permits cover route, dates, vehicle configuration, and axle weights. Changes to equipment or routing require permit review.

Seasonal, route, and local checks

No statewide frost-law or seasonal weight restriction was confirmed for Montana in this review. Montana’s climate and geography do include seasonal conditions that affect certain roads, but a statewide official source wasn’t confirmed. For routes that use rural state or county roads during spring or after significant weather events, checking MDT’s current road and permit conditions is the right approach.

Tickets and enforcement notes

Montana Department of Transportation Motor Carrier Services Enforcement is the confirmed enforcement agency. Montana Code Annotated section 61-10-145 is the official statute reviewed for overweight penalty context. For any citation, the specific MCA section, excess weight, and court instructions are the controlling documents.

Source-strength notes for Montana

This page uses 7 source records and carries 3 high-confidence, 23 medium-confidence, and 3 low-confidence fields. Permit, enforcement, and fine statute fields are well-supported — each has direct official backing. Seasonal fields are where confidence drops — they represent the page’s main sourcing gap.

Building a Montana source file

A Montana dispatch file should include MDT permit documentation, current scale ticket, approved route, and the MCA 61-10-145 reference. For I-90 corridor planning, the axle weight table, permit office list, seasonal restrictions, and overweight fines pages support multi-state Pacific Northwest and Mountain planning.

How to Read a CAT Scale Ticket covers ticket reading. How to Slide Tandems covers distribution. Bridge Formula Explained covers bridge spacing.