The Montana answer
Legal limits
First escort trigger
- Width
- over 12'6"rev. · read · lowest across road classes
- Height
- over 17'rev. · read
- Length
- over 150'rev. · read · lowest across road classes
- Rear overhang
- No trigger published
- Gross weight
- No trigger published
What the paper costs
- Single-trip base
- $10 · caveat ↓rev. · read
- Transaction / card
- Two official sources disagree5% of the total — versus — 7.5% of the total
- How overweight is priced
- The agency prices it; no published schedule · caveat ↓rev. · read
- Superload above
- The state publishes none
The short version: a Montana single-trip permit starts at $10 before bands, overweight and the transaction charge; an escort is first required at over 12'6" wide; and the load becomes a superload at a gross weight the state does not publish. Everything below carries the Montana document it came from, that document's own revision date, and the date we read it.
1. Where the load goes next
The jurisdictions this one borders, each chip carrying the fact that decides whether that crossing is the expensive one — so the row is itself a small comparison. A multi-state lane is the actual job, and from here it is one click per state rather than a return to an alphabetical index.
2. Montana legal limits
Anything over one of these needs a permit. Every value links to the document that sets it.
| Measure | Legal limit |
|---|---|
| Width | 8'6"rev. · read MCA 61-10-102(1): "Except as provided in subsections (2) and (3), a vehicle, including a bus, unloaded or with load, may not have a total outside width in excess of 102 inches. This width for buses is allowed only on paved highways 20 feet or more in width." EXCLUSIVE ("in excess of") — 102.0 in is legal, 102.1 in is not. Corroborated by MDT's own legal-dimension list: "Width: 8'6" (102") (See also 'Farmer Exemptions')". Safety devices are excluded from the measurement by 61-10-102(4): "A safety device that the department determines by rule adopted pursuant to 61-9-504 to be necessary for safe and efficient operation of motor vehicles is not included in the calculation of width provided in subsection (1)." |
| Height | 14'rev. · read MCA 61-10-103(1): "Except as provided in subsection (2), a vehicle, unladen or with load, may not exceed a height of 14 feet." EXCLUSIVE. 14 FT, NOT 13 FT 6 IN — a 13 ft 9 in load needs no Montana permit, and carrying the 13'6" figure some states use would invent one. Corroborated by MDT's legal-dimension list: "Height: 14'0"". |
| Semitrailer length | 53'rev. · read MCA 61-10-104(2)(a): "When used in a truck tractor-semitrailer combination, the semitrailer may not exceed 53 feet in length, excluding those portions not designed to carry a load, except as provided by 61-10-124." EXCLUSIVE, and note the measuring convention — Montana measures the semitrailer EXCLUDING portions not designed to carry a load, where North Dakota next door measures "including the load thereon". A DOUBLE is stricter and is not held in this field: the same subsection caps the semitrailer and trailer at "28 1/2 feet each in length or 61 feet in combined trailer length", which MDT glosses as "Tractor/Doubles: No length limit, providing neither trailer exceeds 28'6" in length and 61' of combined trailer length." |
| Overall length | None published |
| Kingpin to rear axle | None published |
| Front overhang | None published |
| Rear overhang | None published |
| Gross weight | 131,060 lbrev. · read THE REDUCIBLE-LOAD MAXIMUM, AND IT IS SOURCED TO MDT'S CHART RATHER THAN TO THE STATUTE BECAUSE THE STATUTE STATES NO FLAT GROSS. MDT Gross Vehicle Weight Chart: "Maximum gross weight for reducible loads is 131,060 pounds. 61-10-107 MCA". MCA 61-10-107(1)(a) itself contains no gross figure at all — it states the bridge formula, "W = 500((LN/(N - 1)) + 12N + 36) in which W equals gross weight, L equals wheelbase in feet, and N equals number of axles, except that two consecutive sets of tandem axles may carry a gross load of 34,000 pounds each if the overall distance between the first and last axles of the consecutive sets of tandem axles is 36 feet or more", and then delegates: "The maximum gross weight allowed on a vehicle may not exceed the weight limits adopted by the department. The department shall adopt rules for weight limits based upon the most recent version of 23 CFR, part 658, appendix c, for vehicles operating in Montana." The departmental rule could not be located as a specific ARM citation (rules.mt.gov is a JavaScript app returning AccessDenied on its API), so MDT's own published ceiling is the operative figure. THERE IS NO 80,000 lb NUMBER IN 61-10-107: writing one against an MCA cite would invent a permit requirement on 51,060 lb of legal Montana payload and, because the overweight fee is charged on the excess over the legal limit, invent a fee with it. On the Interstate the federal 80,000 lb of 23 U.S.C. 127 governs by federal operation, not by any Montana figure — 61-10-107(3) switches the section off there "when application of this section would prevent this state from receiving federal funds for highway purposes". Two versions of 61-10-107 are in force-pending at once, a "(Temporary)" one carrying a U.S. 93 / MT 16 border carve-out at (1)(b) and an "(Effective on occurrence of contingency)" one that omits it; both carry identical 20,000 / 34,000 / formula figures. |
| Single axle | 20,000 lbrev. · read MCA 61-10-107(1)(a): "An axle may not carry a load in excess of 20,000 pounds... An axle load is the total load transmitted to the road by all wheels whose centers are included between two parallel transverse vertical planes 40 inches apart, extending across the full width of the vehicle. For purposes of this section, axles 40 inches or less apart are considered to be a single axle." EXCLUSIVE. MDT adds a steering-axle rule this engine does not evaluate, because a quote states no tyre dimensions: "Steering axles are limited to the Manufacturers Rated Capacity stamped on the sidewall of the tires not to exceed 20,000 pounds." A separate side-condition at 61-10-107(2)(a) can make a permit unissuable rather than merely dearer: "except for the steering axle, all axles weighing over 11,000 pounds must have at least four tires or have wide-base tires. The maximum load on an axle, other than a steering axle, equipped with wide-base tires is limited to 500 pounds for each inch of tire width." |
| Tandem axle | 34,000 lbrev. · read MCA 61-10-107(1)(a): "and no two consecutive axles more than 40 inches or less than 96 inches apart may carry a load in excess of 34,000 pounds." EXCLUSIVE, and the federal figure — unlike Wyoming next door, which publishes 36,000. MDT restates it: "Tandem-Axle Weight No two consecutive axles more than 40 inches or less than 96 inches apart may carry a load in excess of 34,000 pounds." THIS IS THE NUMBER THE OVERWEIGHT FEE COUNTS FROM: MCA 61-10-125(4) charges on "the sum of excess in axle or axle group weights" measured over the 20,000 lb single, 34,000 lb tandem and formula group limits of 61-10-107(1), not over gross weight. |
3. The Montana escort ladder
Not one number per dimension — the whole staircase. Each row is a condition the state actually publishes, what it requires when that condition holds, and the clause it comes from. Where a rule requires escorts and the source states no number, the row says that in the source's own words rather than reporting no requirement.
| When | What is required | Source |
|---|---|---|
| the road is “non interstate” and width from 12'6" (exclusive) to 16'6" | 1 in front |
PRIMARY, "Updated 07/27/2026". The agency's o…rev. · read |
| the road is “interstate” and width from 16'6" (exclusive) to 18' | 1 behindAdvisory: MDT Permit Restrictions 36a adds a clause this engine does not evaluate: "Vehicles exempted under 61-10-102(2)(a), MCA may only travel during hours of darkness with one rear pilot vehicle per ARM 18.8.511A(1)(b)(i)". Whether this load is one of the 61-10-102(2)(a) exempt vehicles is not stated on a quote, so the rear car is priced on the width trigger alone and the darkness restriction on the exempt class is stated rather than applied. |
PRIMARY, "Updated 07/27/2026". The agency's o…rev. · read |
| the road is “non interstate” and width from 16'6" (exclusive) to 18' | 1 in front1 behindAdvisory: MDT Permit Restrictions 37b adds an exemption this engine does not evaluate: "Loads exempted under 61-10-102(5) shall not require a rear pilot vehicle." Whether this load falls inside 61-10-102(5) is not stated on a quote, so both cars are priced and the exemption is stated — a load that qualifies owes one front car rather than two vehicles. |
PRIMARY, "Updated 07/27/2026". The agency's o…rev. · read |
| height from 17' (exclusive) to 24' | 1 in frontHeight pole required |
PRIMARY, "Updated 07/27/2026". The agency's o…rev. · read |
| the road is “interstate” and width over 18' | 2 behindEscorts required; the source states no number — at least 2. Published as: “Pilot vehicle requirements: (Interstate only) loads exceeding 18 feet wide must have at least two rear pilot vehicles side by side. Vehicles exempted under 61-10-102(2)(a), MCA may only travel during hours of darkness with two rear pilot vehicles per ARM 18.8.511A(1)(b)(ii).” |
PRIMARY, "Updated 07/27/2026". The agency's o…rev. · read |
| the road is “non interstate” and width from 18' (exclusive) to 24' | 2 in front1 behindEscorts required; the source states no number — at least 3. Published as: “Pilot vehicle requirements: (non-interstate only) loads exceeding 18 feet wide to 24 feet wide must have at least two front and one rear pilot vehicles per ARM 18.8.511A(1)(a)(iii).” |
PRIMARY, "Updated 07/27/2026". The agency's o…rev. · read |
| height over 24' | 1 in front1 behindHeight pole required |
PRIMARY, "Updated 07/27/2026". The agency's o…rev. · read |
| the road is “non interstate” and width over 24' | 2 in front2 behindEscorts required; the source states no number — at least 4. Published as: “Pilot vehicle requirements: (non-interstate only) loads exceeding 24 feet wide must have at least two front and two rear pilot vehicles per ARM 18.8.511A(1)(a)(iv).” |
PRIMARY, "Updated 07/27/2026". The agency's o…rev. · read |
| the road is “non interstate” and overall length over 150' | 1 behind |
PRIMARY, "Updated 07/27/2026". The agency's o…rev. · read |
| the road is “non interstate” and overall length over 200' | 1 in front1 behind |
PRIMARY, "Updated 07/27/2026". The agency's o…rev. · read |
The first trigger in each dimension
| Measurement | First escort trigger | First police escort trigger |
|---|---|---|
| Width | over 12'6"rev. · read · varies by road class | None published |
| Height | over 17'rev. · read | None published |
| Length | over 150'rev. · read · varies by road class | None published |
| Rear overhang | None published | None published |
| Gross weight | None published | None published |
The same rules restated in plain sentences13 rules
- Interstate, over 16 ft 6 in up to 18 ft wide — one rear pilot vehicle — PRIMARY, "Updated 07/27/2026". The agency's own numbered restriction list and the source of all ten pilot-vehicle thresholds (restrictions 36a-36d for the Interstate and the height rules, 37a-37f for the non-interstate), the 15-minute traffic-delay cap (restriction 27), the class 1 and class 2 superload restatements (restrictions 28 and 29), the 15 ft log-overhang restatement (restriction 6) and the General Conditions sentence that a county or city permit may be required in addition to the state permit. Each threshold cites its ARM rule number, which is how the secondary Cornell copies were cross-checked. rev. · read
- Interstate, over 18 ft wide — at least two rear pilot vehicles side by side — PRIMARY, "Updated 07/27/2026". The agency's own numbered restriction list and the source of all ten pilot-vehicle thresholds (restrictions 36a-36d for the Interstate and the height rules, 37a-37f for the non-interstate), the 15-minute traffic-delay cap (restriction 27), the class 1 and class 2 superload restatements (restrictions 28 and 29), the 15 ft log-overhang restatement (restriction 6) and the General Conditions sentence that a county or city permit may be required in addition to the state permit. Each threshold cites its ARM rule number, which is how the secondary Cornell copies were cross-checked. rev. · read
- Non-interstate, over 12 ft 6 in up to 16 ft 6 in wide — one front pilot vehicle — PRIMARY, "Updated 07/27/2026". The agency's own numbered restriction list and the source of all ten pilot-vehicle thresholds (restrictions 36a-36d for the Interstate and the height rules, 37a-37f for the non-interstate), the 15-minute traffic-delay cap (restriction 27), the class 1 and class 2 superload restatements (restrictions 28 and 29), the 15 ft log-overhang restatement (restriction 6) and the General Conditions sentence that a county or city permit may be required in addition to the state permit. Each threshold cites its ARM rule number, which is how the secondary Cornell copies were cross-checked. rev. · read
- Non-interstate, over 16 ft 6 in up to 18 ft wide — one front and one rear pilot vehicle — PRIMARY, "Updated 07/27/2026". The agency's own numbered restriction list and the source of all ten pilot-vehicle thresholds (restrictions 36a-36d for the Interstate and the height rules, 37a-37f for the non-interstate), the 15-minute traffic-delay cap (restriction 27), the class 1 and class 2 superload restatements (restrictions 28 and 29), the 15 ft log-overhang restatement (restriction 6) and the General Conditions sentence that a county or city permit may be required in addition to the state permit. Each threshold cites its ARM rule number, which is how the secondary Cornell copies were cross-checked. rev. · read
- Non-interstate, over 18 ft up to 24 ft wide — at least two front and one rear pilot vehicle — PRIMARY, "Updated 07/27/2026". The agency's own numbered restriction list and the source of all ten pilot-vehicle thresholds (restrictions 36a-36d for the Interstate and the height rules, 37a-37f for the non-interstate), the 15-minute traffic-delay cap (restriction 27), the class 1 and class 2 superload restatements (restrictions 28 and 29), the 15 ft log-overhang restatement (restriction 6) and the General Conditions sentence that a county or city permit may be required in addition to the state permit. Each threshold cites its ARM rule number, which is how the secondary Cornell copies were cross-checked. rev. · read
- Non-interstate, over 24 ft wide — at least two front and two rear pilot vehicles — PRIMARY, "Updated 07/27/2026". The agency's own numbered restriction list and the source of all ten pilot-vehicle thresholds (restrictions 36a-36d for the Interstate and the height rules, 37a-37f for the non-interstate), the 15-minute traffic-delay cap (restriction 27), the class 1 and class 2 superload restatements (restrictions 28 and 29), the 15 ft log-overhang restatement (restriction 6) and the General Conditions sentence that a county or city permit may be required in addition to the state permit. Each threshold cites its ARM rule number, which is how the secondary Cornell copies were cross-checked. rev. · read
- Non-interstate, over 150 ft long — one rear pilot vehicle — PRIMARY, "Updated 07/27/2026". The agency's own numbered restriction list and the source of all ten pilot-vehicle thresholds (restrictions 36a-36d for the Interstate and the height rules, 37a-37f for the non-interstate), the 15-minute traffic-delay cap (restriction 27), the class 1 and class 2 superload restatements (restrictions 28 and 29), the 15 ft log-overhang restatement (restriction 6) and the General Conditions sentence that a county or city permit may be required in addition to the state permit. Each threshold cites its ARM rule number, which is how the secondary Cornell copies were cross-checked. rev. · read
- Non-interstate, over 200 ft long — one front and one rear pilot vehicle — PRIMARY, "Updated 07/27/2026". The agency's own numbered restriction list and the source of all ten pilot-vehicle thresholds (restrictions 36a-36d for the Interstate and the height rules, 37a-37f for the non-interstate), the 15-minute traffic-delay cap (restriction 27), the class 1 and class 2 superload restatements (restrictions 28 and 29), the 15 ft log-overhang restatement (restriction 6) and the General Conditions sentence that a county or city permit may be required in addition to the state permit. Each threshold cites its ARM rule number, which is how the secondary Cornell copies were cross-checked. rev. · read
- Over 17 ft up to 24 ft high — one front pilot vehicle with a height pole, on any road class — PRIMARY, "Updated 07/27/2026". The agency's own numbered restriction list and the source of all ten pilot-vehicle thresholds (restrictions 36a-36d for the Interstate and the height rules, 37a-37f for the non-interstate), the 15-minute traffic-delay cap (restriction 27), the class 1 and class 2 superload restatements (restrictions 28 and 29), the 15 ft log-overhang restatement (restriction 6) and the General Conditions sentence that a county or city permit may be required in addition to the state permit. Each threshold cites its ARM rule number, which is how the secondary Cornell copies were cross-checked. rev. · read
- Over 24 ft high — one front pilot vehicle with a height pole and one rear pilot vehicle, on any road class — PRIMARY, "Updated 07/27/2026". The agency's own numbered restriction list and the source of all ten pilot-vehicle thresholds (restrictions 36a-36d for the Interstate and the height rules, 37a-37f for the non-interstate), the 15-minute traffic-delay cap (restriction 27), the class 1 and class 2 superload restatements (restrictions 28 and 29), the 15 ft log-overhang restatement (restriction 6) and the General Conditions sentence that a county or city permit may be required in addition to the state permit. Each threshold cites its ARM rule number, which is how the secondary Cornell copies were cross-checked. rev. · read
- Overweight on a non-interstate route — pilot cars may be added by MDT's bridge travel condition, which no dimension predicts — PRIMARY, "Revised 04/08/2026". Source of the superload entry trigger and all three class definitions with their "exceeds / does not exceed" wording, the two- and five-working-day decision clocks, the nine conditions the department may attach, the weight-triggered pilot-car travel conditions on p.6, and the tribal/city/county contact requirement on p.3. Read in full and states NO superload fee. rev. · read
- Over 75 ft overall — Montana's 75 ft cap applies only to loads extending beyond the carrying portion of the trailer — PRIMARY, the issuing agency's own manual, "NINTH EDITION – April 2026 (online only)". Sole source of the 131,060 lb reducible-load maximum ("Maximum gross weight for reducible loads is 131,060 pounds. 61-10-107 MCA", Gross Vehicle Weight Chart pp.14-16). Also restates the $10 trip oversize fee (p.25), the $10/$30/$50 bridge-formula distance bands and the full overweight fee table with MDT's own worked example (pp.28-29), the Bridge Centerline travel condition (p.29) and the 9-axle bridge-review trigger (p.30). rev. · read
- Pilot-vehicle operating conditions — 15-minute traffic-delay cap, and the ARM 18.8.510A equipment spec is not on file — PRIMARY, "Updated 07/27/2026". The agency's own numbered restriction list and the source of all ten pilot-vehicle thresholds (restrictions 36a-36d for the Interstate and the height rules, 37a-37f for the non-interstate), the 15-minute traffic-delay cap (restriction 27), the class 1 and class 2 superload restatements (restrictions 28 and 29), the 15 ft log-overhang restatement (restriction 6) and the General Conditions sentence that a county or city permit may be required in addition to the state permit. Each threshold cites its ARM rule number, which is how the secondary Cornell copies were cross-checked. rev. · read
4. Montana single-trip permit fees
| Charge | Amount |
|---|---|
| Single-trip base | $10rev. · read MCA 61-10-124(1): "Except as provided in subsections (2)(d) and (3), in addition to the regular registration and gross vehicle weight fees, a fee of $10 for each trip permit and a fee of $75 for each term permit issued for size in excess of that specified in 61-10-101 through 61-10-104 must be paid for all movements under special permits on the public highways under the jurisdiction of the department of transportation." FLAT, not banded and not per-mile. Both the "(Temporary)" and the "(Effective on occurrence of contingency)" versions carry the identical $10/$75 figures. Corroborated by MDT's own fee block: "Single Trip Over-Dimensional Permits — For loads exceeding 8' 6" wide, 75' long, 14' high; Single unit 55' long. Permit Fees — Trip Oversize $ 10.00 — Triples Permit $ 20.00". TWO PER-TRIP EXCEPTIONS ARE NOT APPLIED because neither is the ordinary product: a triples / truck-trailer-trailer / tractor-semitrailer-trailer-trailer combination pays "$200 for a term permit or $20 for each trip permit" under 61-10-124(3)(f), and a platoon operation pays "$200 for a term permit or $20 for each trip" under 61-10-124(4)(d). NO SEPARATE ISSUANCE OR PROCESSING CHARGE EXISTS: 61-10-124 and 61-10-125 were read in full and the handbook's fee pages with them, and the only $10 admin add-on in the statute attaches to a TERM overweight permit "if the fee is paid other than annually" (61-10-125(3)(b)), never to a trip permit. The permit also carries an insurance condition rather than a fee — "Insurance requirements are a minimum of $1,000,000 combined single limit bodily injury and property damage liability per occurrence" — and MDT notes "All trip permits are void upon leaving the state." |
| Transaction / card | Two official sources disagree5% of the total — versus — 7.5% of the total |
| Route analysis review | Not yet covered |
| Route with no bridges | Not yet covered |
Montana has more than one permit issuer. A state total can be complete and still be missing a whole permit.
- Montana county and city road authorities — Any travel on a county road or a city street. MDT's own General Conditions: "A county or city permit may be required in addition to this permit for travel on county roads or city streets." MCA 61-10-121(1)(a) grants the power to "the department of transportation, or its agent under subsection (4), and local authorities in their respective jurisdictions ... upon a highway under the jurisdiction of and for the maintenance of which the body granting the permit is responsible", and 61-10-121(5) bounds it: a local authority may not "require a fee and a permit for the movement of a vehicle ... of a size exceeding the maximum specified in 61-10-101 through 61-10-104 on a highway that is under the jurisdiction of an entity other than the local authority." The state keeps the biggest loads: "only the department may issue permits for movement of a vehicle or combination of vehicles carrying built-up or reducible loads in excess of 9 feet in width or exceeding the length, height, or weight specified in 61-10-101 through 61-10-104 and 61-10-106 through 61-10-110.". We do not hold this authority's fee schedule, so the leg goes to review rather than being quoted short. Montana Permit Restrictions — eTRIPs
5. How Montana prices overweight
The agency prices it; no published schedule. Montana publishes BOTH of its single-trip overweight charges in full and this engine can compute neither from a gross weight. MCA 61-10-125(1) charges a load "over the gross allowable load provided for by the formula in 61-10-107 (1) but that does not exceed axle limits set forth in 61-10-107 (1)" a flat "$10 for distances up to and including 100 miles; $30 for distances from 101 to 199 miles; and $50 for distances 200 miles and over". MCA 61-10-125(4) charges a load that "exceeds the single axle, tandem axle, or axle group limits set forth in 61-10-107 (1)" a per-mile fee "based upon the sum of excess in axle or axle group weights", read off a table of "Total Excess Axle Weight (pounds)" against the "Calculated Cost of 25 Miles of Travel (dollars)" — $3.50 per 5,000 lb of excess per 25 miles, rising linearly to $70.00 at 100,000 lb and then "70.00 + 3.50 per 5,000 lbs. or part of 5,000 lbs. in excess of 100,000 lbs." TWO THINGS STOP IT. First, the charged quantity is the SUM OF THE PER-AXLE AND PER-AXLE-GROUP EXCESSES, not the gross: in MDT's own worked example a 187,000 lb load is charged on 31,250 lb, and the 155,750 lb difference is that configuration's own axle allowance rather than any published constant. Second, which of the two charges applies turns on whether an AXLE limit is exceeded, and defaulting to the cheaper one would have billed $50 where MDT bills $392.00 for 31,250 lb of excess over 389 miles. The full table, the rate and the state's two-direction rounding rules are on file as MONTANA_OVERWEIGHT_FEE_TABLE_25MI, MONTANA_OVERWEIGHT_EXCESS_AXLE_WEIGHT_RATE and MONTANA_BRIDGE_FORMULA_DISTANCE_BANDS, so the amount is a one-minute hand calculation once the axle weights are known: round the total excess up to the next 5,000 lb, read the 25-mile rate, round the Montana miles up to the next 25, and multiply.
A SCHEMA LIMIT, NOT A RESEARCH GAP — and the distinction is the point. Every figure Montana publishes for both overweight charges is on file, cited, and reproduces MDT's own worked example to the cent; what is missing is a way to hand `PerMileRate` the TOTAL EXCESS AXLE WEIGHT instead of the gross, and a `ContextCondition` leaf for "the load exceeds an axle limit" to tell the two charges apart. Flip this row to `perMile` and move MONTANA_OVERWEIGHT_EXCESS_AXLE_WEIGHT_RATE into `overweightPerMile` unchanged the moment both exist.There is no weight schedule to print, and under this model there is not supposed to be one.
6. Montana seasonal posting windows
A permit priced against an unposted-road assumption in March is simply wrong, and wrong in the expensive direction. This is the window we watch, the basis for that window in the state's own orders or statute, and the authority that posts it.
Seasonal posting
- Programme
- A statewide seasonal programmePublished through the statewide travel-information map rather than as a bulletin, so we link to it and watch it for change rather than claiming a parsed limit.
- Posting window we watch
- 02-01 → 05-31MDT posts spring break-up restrictions through its travel-information system as districts thaw; no fixed statutory season is published, so the window is the observed spread of MDT restriction notices.
- Issuing authority
- MDT — Travel Information: restrictionsMontana Department of Transportation
The live Montana restriction picture, with the date we last read the bulletin →
7. Montana's superload threshold
Above one of these, the state stops issuing over the counter and prices the move after an engineering review.
| Trigger | Threshold |
|---|---|
| Gross weight | None published |
| Width | over 18'rev. · read Entry trigger: "Loads which exceed 18 feet in width, 150 feet in length, 17 feet in height, or which require approval by the department's Bridge Bureau due to the weight, truck configuration, and/or route must apply for a Superload permit." Class 1: "width exceeds 18 feet but does not exceed 34 feet"; class 2: "width exceeds 34 feet". `inclusive: false` IS READ, NOT ASSUMED — the source's word is "exceeds", so exactly 18 ft 0 in is not a superload and 18 ft 1 in is class 1. Corroborated verbatim in MDT Permit Restrictions 28: "Superload (class 1) – Loads exceeding 18 feet wide up to 34 feet wide, 17 feet high up to 24 feet high, and/or 150 feet long up to 200 feet long, must obtain the appropriate department district administrator or designee approval of a completed super-load permit application." Class 1 carries a two-working-day decision clock and class 2 a five-working-day one; class 1 and 2 applications are "good for sixty days from approval" and class 3 for one year. ARM 18.8.509 (SECONDARY, Cornell LII) matches on classes 1 and 2 and does not list the weight-based class 3. |
| Height | over 17'rev. · read Class 1: "height exceeds 17 feet but does not exceed 24 feet"; class 2: "height exceeds 24 feet". `inclusive: false` because the word is "exceeds" — exactly 17 ft 0 in is not a superload. NOTE THE 17 FT SUPERLOAD FLOOR SITS EXACTLY ON THE HEIGHT PILOT-CAR FLOOR: the same 17 ft that takes a front car with a height pole under restriction 36c also makes the load a class 1 superload, so a 17 ft 6 in Montana move needs both. Restated in MDT Permit Restrictions 28 and 29. |
| Length | over 150'rev. · read Class 1: "length exceeds 150 feet but does not exceed 200 feet overall length"; class 2: "length exceeds 200 feet". `inclusive: false` for the same read-not-assumed reason. 150 FT IS ALSO THE NON-INTERSTATE REAR-PILOT-CAR FLOOR (restriction 37e), so the two ladders meet here as they do at 17 ft of height. Class 3 is the mirror image of all three dimensional triggers: "weight requires approval of the department's bridge bureau; and width does not exceed 18 feet; height does not exceed 17 feet; length does not exceed 150 feet" — a superload by weight alone, which no dimensional threshold detects. |
| Short axle spacing | Not yet covered |
8. Route survey and bridge review
The dimensions at which Montana triggers a physical route inspection or an engineering review, and what the agency charges to review it.
| Measurement | Inspection / review trigger |
|---|---|
| Width | Not yet covered |
| Height | Not yet covered |
| Length | Not yet covered |
9. Police escorts
We hold no police escort finding for Montana.
10. When you can move it
Holiday, curfew and night-travel windows are not yet encoded for Montana. The seasonal picture — which is a different question — is in section 6 above.
Why those windows are absent rather than estimated
They are not guessed at here. What we do publish is the seasonal weight-restriction picture, with the date we last read each state's own bulletin — a curfew invented from a plausible pattern is worth less than an honest gap, because a reader cannot tell the two apart on the page.
11. Permit office
The agency behind each figure above is linked from that figure. We publish no per-state permit-office phone number.
Why there is no phone number here
We are not publishing per-state permit-office phone numbers yet, and the reason is worth stating: the two seed lists available for them are both demonstrably stale — the federal one gives two different states the same phone number — and a wrong number on a page like this costs somebody a morning. The agency behind each figure above is linked from that figure, which is the part we can stand behind today.
12. What this does not include
Named rather than gestured at, because each of these can exceed the permit itself. Every item is listed; open one for why it is excluded.
Line haul, fuel and driver time
This is a permit fee, not a freight rate.
Civilian pilot car rates
We hold no rate data, and the two commercial sites that publish market rates disagree by nearly a factor of two on the same service.
Route-survey engineering
The agency's review fee is shown where the state publishes one; the engineer's own fee is a private cost with no schedule.
Bonds and escrow
Set per move by the agency, and in at least one state the escort is billed at actual cost against it.
Utility coordination and line lifts
Arranged with each utility, priced by each utility.
Second-issuer permits
A toll, bridge or city authority inside the same state issues its own permit, and a state total that omits it is missing a whole permit.
Need a pilot car for this lane? Browse the pilot car & escort directory.
13. Every source behind this page (6)
Every document behind Montana6 sources
- 2026 Montana Commercial Vehicle Size and Weight and Safety Trucker's Handbook (ninth edition) — Montana Department of Transportation, Motor Carrier Services Division — PRIMARY, the issuing agency's own manual, "NINTH EDITION – April 2026 (online only)". Sole source of the 131,060 lb reducible-load maximum ("Maximum gross weight for reducible loads is 131,060 pounds. 61-10-107 MCA", Gross Vehicle Weight Chart pp.14-16). Also restates the $10 trip oversize fee (p.25), the $10/$30/$50 bridge-formula distance bands and the full overweight fee table with MDT's own worked example (pp.28-29), the Bridge Centerline travel condition (p.29) and the 9-axle bridge-review trigger (p.30).
rev. · read - DOA Rate Sheet — Online Payment Portal fees — Montana Department of Administration, State Information Technology Services Division — PRIMARY. Dated September 8, 2025 and states its fees apply "as of October 1, 2025": "Transaction Fee 5% / Min - $0.50 charge / transaction / Max - $10.00 charge / transaction — Network Fee 2.5% — Chargeback $25". Linked from MDT's ePART pages; no equivalent sheet is published for the ProMiles-hosted eTRIPS portal that took over OS/OW permits in December 2025, which is the unresolved scope recorded on both transaction-fee rows.
rev. · read - Mont. Admin. r. 18.8.511A — When pilot vehicles are required — Montana Secretary of State (via Cornell Legal Information Institute) — SECONDARY — Cornell LII's copy, effective 2020-08-29, for the same rules.mt.gov reason. Every threshold it carries is restated verbatim in MDT's PRIMARY Permit Restrictions with the matching ARM subsection cited, and the two agree on every figure. Cited here for the escalation rule MDT does not restate: "In the event a load meets more than one of the criteria ... the criteria requiring the greatest number of pilot vehicles will determine the number."
rev. · read secondary host - Montana Code Annotated 2025, Title 61 chapter 10 part 1 — size, weight and load — Montana Legislative Services Division — PRIMARY, from the state legislature's own statute host. Source of the 102 in width (61-10-102(1)), the 14 ft height (61-10-103(1)), the 53 ft semitrailer and the uncapped tractor-semitrailer combination (61-10-104(2)(a)), the 20,000 lb single axle and 34,000 lb tandem and the bridge formula with its delegation to a departmental rule (61-10-107(1)(a)), the $10 trip oversize fee (61-10-124(1)), both overweight charges and the two-direction rounding rule (61-10-125(1), (4) and (5)), and the local-authority permitting power (61-10-121). The site states only the title year.
rev. · read - Montana Permit Restrictions — eTRIPs — Montana Department of Transportation, Motor Carrier Services Division — PRIMARY, "Updated 07/27/2026". The agency's own numbered restriction list and the source of all ten pilot-vehicle thresholds (restrictions 36a-36d for the Interstate and the height rules, 37a-37f for the non-interstate), the 15-minute traffic-delay cap (restriction 27), the class 1 and class 2 superload restatements (restrictions 28 and 29), the 15 ft log-overhang restatement (restriction 6) and the General Conditions sentence that a county or city permit may be required in addition to the state permit. Each threshold cites its ARM rule number, which is how the secondary Cornell copies were cross-checked.
rev. · read - Superload Application Instructions and Information — Montana Department of Transportation, Motor Carrier Services Division — PRIMARY, "Revised 04/08/2026". Source of the superload entry trigger and all three class definitions with their "exceeds / does not exceed" wording, the two- and five-working-day decision clocks, the nine conditions the department may attach, the weight-triggered pilot-car travel conditions on p.6, and the tribal/city/county contact requirement on p.3. Read in full and states NO superload fee.
rev. · read
Questions
How much is an oversize permit in Montana?
The single-trip base is $10, before the dimension bands, the overweight component and the transaction charge. The base alone is rarely what is paid.
When does Montana require a pilot car?
The first width trigger is over 12'6", and it varies by road class — the figure shown is the lowest across classes.
What is a superload in Montana?
Montana publishes no gross-weight superload threshold in the documents on file — see the superload section, which shows the dimensional triggers it does publish.