Legal size & loaded measurements
General width
8′6″Ordinary vehicle-and-load limit; safety-device, vehicle and load exceptions may apply.
Loaded height
14′Ordinary vehicle-and-load limit; listed exceptions and actual route clearances apply.
Loaded dimensions
Montana baselines are 102 inches width and 14 feet height; length depends on single-unit, semitrailer, doubles, pole/log and other configuration.
Axles, weight & bridges
Use tire limits, axle/group spacing, bridge formula, gross weight, registration, road class, bridge postings and route restrictions; GVW alone is not a Montana answer.
Permits, routes & larger loads
Roads & authorities
MDT permits cover the state highway system named on the permit. County, city and tribal roads require their own authority and contacts, and route ownership must be confirmed.
When a permit is needed
Overlegal size or weight needs the applicable Montana special permit before movement. Dated trip, term and scoped products have different limits and validity.
Larger-load review
Term bands reach 15 feet width, 15 feet 6 inches height and 95 feet length, with scoped 120-foot, mobile-home, triples and 100-foot products. Superload review starts above 18 feet/17 feet/150 feet or Bridge Bureau weight review.
State permit fees
Single-trip agency fee example
$10 for this Montana planning example: a nondivisible load measuring 8′7″ wide, 13′ high and 70′ overall, at 72,000 lb gross on a five-axle rig with a 48′ trailer. The example uses 100 in-state miles. Change the load details in the calculator for your move.
What the agency estimate includes
The calculator applies Montana's maintained single-trip permit schedule to the loaded vehicle and the supplied fee inputs. It itemizes the supported state charges, including weight or distance charges where applicable. Annual permits, special products, local permissions and payment-method charges need their own applicable schedule.
MT / Permit worksheet
Price your Montana movement.
Enter the complete loaded vehicle. Get estimated agency fees and escort requirements before sharing your contact details.
The numbers behind your next move.
Your result will show the agency fee breakdown, potential pilot-car requirements, and the rules used to calculate them.
- 01 State agency fee subtotal
- 02 Escort & survey considerations
- 03 Sources & pricing assumptions
Single-state pricing uses the mileage you enter. For a proposed route and intermediate states, use the route calculator.
About the example equipment
The samples use ODPermit’s editable 48 ft flatbed · 5 axles planning profile. Loaded dimensions, gross weight, 100 state miles and Texas registration are example inputs, not a capacity rating or a route approval. Replace them with your actual setup.
Great Dane Freedom trailer specifications — 48 ft platform; the illustrated 40 in drop deck and 20 in drop support a 60 in upper-deck planning height. Combined tare and tractor geometry are editable ODPermit assumptions.
Pilot cars, height poles & surveys
14′6″-wide load example
Example: 14′6″ wide × 13′ high, 75′ overall, 72,000 lb gross, zero overhang or rear projection, ordinary nondivisible freight in daylight. Non-Interstate highways: at least 1 civilian car. Interstate highways: at least 0 civilian cars. Montana uses the largest applicable dimensional crew, not the sum of each trigger; the permit reconciles combined position requirements. Non-Interstate: 1 front. Interstate: no width escort. These positions describe the width crew within the plan.
17′6″-high load example
Example: 9′ wide × 17′6″ high, 75′ overall, 72,000 lb gross, zero overhang or rear projection, ordinary nondivisible freight in daylight. Non-Interstate highways: at least 1 civilian car. Interstate highways: at least 1 civilian car. Montana uses the largest applicable dimensional crew, not the sum of each trigger; the permit reconciles combined position requirements. The front car needs a pole or equivalent height detector; above 24 ft, a rear car is also specified. Combined width/height positions need the permit's assignment.
Travel hours & road restrictions
Travel hours
Interstate permits can allow 24/7 up to 18 feet width; non-interstate 24/7 travel is limited to the published envelope, while larger moves use daylight or permit-specific windows.
Current route restrictions
Check 2026 holiday dates, weekend/severe-condition restrictions, 511 closures, bridge postings, construction, school-bus conflicts and every numbered condition on the permit.
Signs, flags & safety equipment
Safety equipment
Use required oversize signs, flags, amber lights, two-way radio, full-length lighting, bridge speed/spacing controls, securement and all traffic-control conditions on the permit.
What the driver needs
Carry the permit
Carry a legible paper or electronic permit, every page and attachment, and present it to enforcement; a permit does not replace local authority or route checks.
Prepare the driver packet
The packet must match the vehicle/load, route, dates, dimensions, axle diagram, bridge analysis, pilot plan, insurance, local contacts and every permit attachment.
Special equipment & permit programs
Special permit programs
Mobile homes, raw logs, hay, triples, 100-foot doubles, custom combines, winter weight, marine equipment and class 1/2/3 superloads have scoped conditions.
BEFORE THE TRUCK ROLLS
Turn the estimate
into a permitted move.
Confirm the loaded measurements, carrier details, travel dates and exact pickup and delivery. We can help coordinate permits, escorts and route surveys around those facts.
THE SOURCE RECORD
Official references.
Read the rule behind each requirement. These are dated references; current restrictions and the issued permit control your move.
- 01
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- 03
- 04
- 05
- 06Superload Application Instructions and Information
Railroad Crossings; Traffic control plan; Additional Required Documents · Page 3
Source record: - 07
- 08
- 09Montana Commercial Vehicle Size and Weight and Safety Trucker's Handbook
Maximum Term Permit Dimensions · Page 23
Source record: - 10
- 11MCA61-10-125 — gross-only and excess-axle trip fees
MCA61-10-125 — gross-only and excess-axle trip fees
Source record: - 12
- 13
- 14MDT permitting reference — January 2026, pages 14–17
MDT permitting reference — January 2026, pages 14–17
Source record: - 15Montana ARM 18.8.511A — March 21, 2026 adoption
Montana ARM 18.8.511A — March 21, 2026 adoption
Source record: - 16MDT permitting reference — January 2026, pages 14–17
MDT permitting reference — January 2026, pages 14–17
Source record: - 17Montana ARM 18.8.511A — March 21, 2026 adoption
Montana ARM 18.8.511A — March 21, 2026 adoption
Source record: - 18
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