The short version: a Tennessee single-trip permit starts at $20 before bands, overweight and the transaction charge; an escort is first required at over 10' wide; and the load becomes a superload at over 165,000 lb. Everything below carries the Tennessee document it came from, that document's own revision date, and the date we read it.
Corridor
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.
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 secondary host§ 55-7-202(c): "Motor vehicles not exceeding eight feet six inches (8′ 6″) in width are permitted to operate over the interstate system and other federal-aid highways designated by the commissioner." INCLUSIVE. § 55-7-202(d) states the same 8 ft 6 in for the federal and state highway system: "whose width, including any part of the load, does not exceed eight feet six inches (8′ 6″) (that is, four feet three inches (4′ 3″) on each side of the center line of the vehicle)". § 55-7-202(a)(1) sets 8 ft as the general limit and is carried as an advisory rather than recorded here.
Height
13'6"rev. · read secondary host§ 55-7-202: no vehicle "whose height, including any part of the load, exceeds thirteen and one-half feet (13½′), shall be operated on any highway". EXCLUSIVE — exactly 13 ft 6 in is legal, and § 55-7-202(d) reaffirms it from the other side as "does not exceed thirteen feet six inches (13′ 6″)".
Semitrailer length
52'rev. · read secondary host§ 55-7-201(c): "provided, that the towed vehicle shall not exceed fifty-two feet (52′) in length from the point of attachment to the tractor." INCLUSIVE. TDOT's FAQ separately publishes "Truck Tractor & Semi Trailer 50' from kingpin to rear of trailer", which is a DIFFERENT measurement — kingpin to the rear of the trailer, not the towed vehicle's length and not the kingpin-to-rearmost-axle distance — and is not recorded as a competing value for either field.
Overall length
None published
Kingpin to rear axle
41'rev. · read secondary host§ 55-7-201(c): "If the towed vehicle exceeds forty-eight feet (48′) in length from the point of attachment to the tractor and the load on the vehicle does not consist of livestock, motor vehicle parts, or motor vehicles, or any combination of such items, the distance between the kingpin and a point midway between the two (2) rear axles shall not exceed forty-one feet (41′)." INCLUSIVE, and CONDITIONAL: it binds only a towed vehicle over 48 ft carrying something other than livestock, motor vehicle parts or motor vehicles. This engine applies it whenever a kingpin distance is supplied, which over-states the limit for a trailer of 48 ft or less and for the exempt commodities; a load caught by it on those facts should be confirmed with the TDOT Permit Office.
Front overhang
None published
Rear overhang
None published
Gross weight
80,000 lbrev. · read secondary host§ 55-7-203(b)(3): "The total gross weight of a vehicle, freight motor vehicle, truck-tractor, trailer or semitrailer or combinations of these vehicles operated over, on or upon the public highways of this state shall not exceed eighty thousand pounds (80,000 lbs.)". INCLUSIVE. The same subdivision adds that on the interstate system the total gross weight "shall not exceed the lesser of eighty thousand pounds (80,000 lbs.) or the weight produced by application of" the federal bridge formula, which is implemented in bridgeFormula.ts; the 80,000 lb figure is the flat cap and is what a quote without axle positions can test.
Single axle
20,000 lbrev. · read secondary host§ 55-7-203(b)(1)(A): "No axle shall carry a load in excess of twenty thousand pounds (20,000 lbs.)." EXCLUSIVE.
Tandem axle
34,000 lbrev. · read secondary host§ 55-7-203(b)(2): "The total gross weight concentrated on the highway surface from any tandem axle group shall not exceed thirty-four thousand pounds (34,000 lbs.) for each tandem axle group." INCLUSIVE, with the group defined by a spacing of more than 40 in and not more than 96 in.
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 “tn two lane under 24ft pavement” and width from 10' (exclusive) to 12'6"
1 certified escort1 in frontAdvisory: 1680-07-01-.06(2)(b): "One (1) escort vehicle is required to precede the movement where the minimum pavement width (excluding paved shoulders) is less than twenty-four feet (24')." The same subsection requires NO escort at this width on the interstate system, on a highway with four or more lanes, or on a two-lane highway with 24 ft or more of pavement.
1 certified escortAdvisory: 1680-07-01-.06(3): "One (1) escort vehicle is required to follow the movement on the interstate highway system or highways with four or more lanes. ... One (1) escort vehicle is required to precede the movement on two-lane highways." One car either way; only its position changes with the road, so the road type is not needed to count or to price it.
1 certified escort1 in frontHeight pole requiredAdvisory: 1680-07-01-.10(1)(d): "When the permitted vehicle and load exceeds fifteen feet (15') in height, the permittee shall determine all vertical clearances by use of a front escort vehicle having protrusions equal to, at a minimum, the height of the permitted vehicle and load. The escort vehicle shall be capable of immediately communicating with the permitted vehicle at all times ... The permitted vehicle shall follow the escort vehicle at such a distance and at such a speed as will permit stopping on receipt of advice that any vertical clearance is less than the height of the permitted vehicle and load." TDOT's FAQ states the same requirement as "15'1” and greater Front escort with height pole required" — the same boundary in whole inches — and separately notes that for a ROUTE SURVEY "Height poles should be set at 6” greater than the height of the load", which is a survey specification and not the escort pole's.
2 certified escorts1 in front1 behindRoute survey / engineering review before issueAdvisory: 1680-07-01-.06(5): "Movements in excess of sixteen feet (16') may be permitted, as provided in Rule 1680-07-01-.12, if the movement is not detrimental or unsafe to the traveling public and the highway can accommodate the movement. A route survey shall be required prior to the issuance of a permit." A movement this wide is "extra-overdimensional" under Rule 1680-07-01-.12(1) and is priced by TDOT after review, so no permit amount is quoted for it. The published width fee above 16 ft is $30.00 plus $5.00 for each additional foot or fraction thereof, which is recorded in TENNESSEE_OVER_16FT_WIDTH_FEE and is not applied.
Escorts required; the source states no number — at least 2. Published as: “THP moves require a minimum of two (2) officers for a minimum of four (4) hours.”Cannot be reduced to a number: TDOT FAQ: "When the width of the load exceeds 18' or the height exceeds 18' THP escorts are required. Especially complex movements may also require THP escorts. THP escorts are in addition to other required escorts. The THP Request Form will be required. Once the Permit Office has approved the movement it will be forwarded to THP who will then contact the carrier to schedule the move. THP moves require a minimum of two (2) officers for a minimum of four (4) hours at a rate of $65.00 per hour + $.13/mile." The floor is computable — 2 officers x 4 hours x $65.00 = $520.00, plus $0.13 per mile — but the hours actually charged are set by THP on the day, so no police-escort amount is included in the permit total. Rule 1680-07-01-.12(4) separately lets the Permit Office require law-enforcement escorts on a super-heavy movement with no threshold at all.
$20rev. · read secondary host§ 55-7-205(h): "(1)(A) Not more than fourteen feet (14′), twenty dollars ($20.00)"; "(2) Excessive height or length: Twenty dollars ($20.00)"; "(3) Excessive weight: Twenty dollars ($20.00) plus six cents (6¢) per ton-mile;". One figure reached from three directions, which is why it is the base rather than a band.
Transaction / card
Not yet covered
Route analysis review
Not yet covered
Route with no bridges
Not yet covered
Dimension bands
Band
Fee
up to 14 ft wide — no increment above the $20 base fee
$0rev. · read § 55-7-205(h)(1)(A): "Not more than fourteen feet (14′), twenty dollars ($20.00)". INCLUSIVE — a load measuring exactly 14 ft 0 in is in this band. The $20 IS the base fee held in `permitBaseFeeUsd`, so this band adds nothing and the two together are the published $20. The band bounds width only, which is why an over-height or over-length load within 14 ft also lands here and pays the same $20 the schedule prints for "Excess Height" and "Excess Length".
up to 14 ft wide — no increment above the $20 base fee
$0undated document · read TDOT Permit Prices: "Excess Width: 8'6" up to 14' $20.00", and "Excess Length $20.00" / "Excess Height $20.00" at the same amount.
over 14 ft 1 in up to 16 ft wide — $10 above the base fee
$10rev. · read § 55-7-205(h)(1)(B): "Over fourteen feet (14′) but not more than sixteen feet (16′), thirty dollars ($30.00)" — the $20 base plus this $10 increment. THE FLOOR RECORDED HERE IS 14 FT 1 IN, NOT THE STATUTE'S "over fourteen feet": TDOT's fee table opens the same band at "14'1"", and only the range both documents name is priced. A width strictly between 14 ft 0 in and 14 ft 1 in matches no band and the schedule does not price it. See TENNESSEE_WIDTH_BAND_GAP.
over 14 ft 1 in up to 16 ft wide — $10 above the base fee
$10undated document · read TDOT Permit Prices: "Excess Width: 14'1" up to 16' $30.00" — the $20 base plus this $10 increment. Above 16 ft the table reads "$30.00 + $5 for each additional foot or fraction", which has no flat amount to band and is unreachable behind the 16 ft superload trigger; it is recorded in TENNESSEE_OVER_16FT_WIDTH_FEE.
Priced by the mile. Tenn. Code Ann. § 55-7-205(h)(3) prices the overweight permit at "Twenty dollars ($20.00) plus six cents (6¢) per ton-mile" — a charge that is the PRODUCT of the excess weight and the distance travelled inside the state, not a step by either. It is encoded as a per-mile rate whose increment is a ton, because six cents per ton-mile and six cents per mile for each ton over the lawful weight are the same arithmetic. The statute states no upper weight bound; above 165,000 lb the movement is super heavy and TDOT prices it after an engineering review.
Rounding is not a detail here: the same rate over the same miles can differ by a whole increment depending on which pounds are rounded and in which direction, so the rule is printed with the source's own words rather than applied silently.
Gross weight
Axles
Rate and rounding
Source
80,001 lb and up
any
$0.06 per mile for each 2,000 lb above 80,000 lba part increment is charged in full ("or fraction thereof")
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.
Tennessee is not in the seasonal-restriction registry, so we hold no posting window for it and are not inventing one.
Superload
7. Tennessee'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
over 165,000 lbundated document · read TDOT OS/OW FAQ: "What is considered a Superload? Gross Vehicle Weight in excess of 165,000 pounds". EXCLUSIVE — exactly 165,000 lb is still an ordinary permit. The same answer reproduces Rule 1680-07-01-.12(1): "For the purposes of this rule, 'super heavy' means that the total gross weight of the vehicle and load exceeds 165,000 pounds". That rule was not separately opened and no URL has been invented for it; the FAQ is the document on file that carries the text.
Width
over 16'undated document · read TDOT OS/OW FAQ: "Width in excess of 16'". EXCLUSIVE. Rule 1680-07-01-.12(1), as reproduced in the same answer: "'extra-overdimensional' means that the width of the vehicle and load exceeds sixteen feet (16')".
Height
over 15'6"undated document · read TDOT OS/OW FAQ: "Height in excess of 15'6”". EXCLUSIVE. Rule 1680-07-01-.12(1): "'extra-overdimensional' means that ... the height of the vehicle and load exceeds fifteen feet six inches (15'6")".
The dimensions at which Tennessee triggers a physical route inspection or an engineering review, and what the agency charges to review it.
Measurement
Inspection / review trigger
Width
over 16'undated document · read TDOT OS/OW FAQ: "If the height of the load exceeds 15'6” and/or the width exceeds 16' a route survey will be required." EXCLUSIVE. Corroborated by 1680-07-01-.06(5)(a): "A route survey shall be required prior to the issuance of a permit" for movements over 16 ft wide.
Tennessee codifies no per-application administrative fee, no officer per diem and no cancellation penalty for an OS/OW escort. Their absence from the floor must not be read as their being nil.
Rule 1680-07-01-.12(4) separately lets the Permit Office require law-enforcement escorts on a super-heavy movement with no threshold at all.
Holiday, curfew and night-travel windows are not yet encoded for Tennessee. 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.
Who issues it
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.
Source conflicts
12. Where the sources disagree
Two official documents, both in effect, giving different answers. Neither has been adopted.
route-inspection height trigger
over 15'6"Tenn. Code Ann. § 55-7-205 — Special permits and fees (via Justia — SECONDARY source) — (h)(1)(A)-(D) the width ladder and the houseboat bands; (h)(2) "Excessive height or length: Twenty dollars ($20.00)"; (h)(3) "Excessive weight: Twenty dollars ($20.00) plus six cents (6¢) per ton-mile;"; (h)(4)(A)-(C) the bridge evaluation charges; (l)(1) the ten-day validity; (n)(5)(E)(i) the heavy-duty towing 12¢ ton-mile tier; (p) the route-survey height trigger rev. · read
15' or moreTenn. Comp. R. & Regs. 1680-07-01-.10 — Height pole and route survey (via Cornell LII — SECONDARY source) — (1)(c) the route survey "If the height of the movement is fifteen feet (15') or more"; (1)(d) "When the permitted vehicle and load exceeds fifteen feet (15') in height, the permittee shall determine all vertical clearances by use of a front escort vehicle having protrusions equal to, at a minimum, the height of the permitted vehicle and load." rev. · read
Both are in effect and neither has been adopted.
A width band that opens one inch apart in two documents
Tenn. Code Ann. § 55-7-205(h)(1)(B) opens its $30 band immediately above 14 ft 0 in while TDOT's published fee table opens it at 14 ft 1 in. The $20 band closes at exactly 14 ft 0 in on both readings. A width strictly between 14 ft 0 in and 14 ft 1 in is therefore priced by no band either document publishes, and the permit fee must be confirmed with the TDOT Permit Office.
TENNESSEE_WIDTH_BAND_GAP
3 escort boundaries that decide a requirement, not a price
Between 10' and 10'1": the rule reads "over ten feet (10') wide but not exceeding twelve feet six inches (12'6")" while the agency FAQ reads "10'1” – 12'6”". Between 12'6" and 12'7": the rule reads "over twelve feet six inches (12'6") wide but not exceeding thirteen feet six inches (13'6")" while the agency FAQ reads "12'7” – 13'6”". Between 13'6" and 13'7": the rule reads "over thirteen feet six inches (13'6") wide but not exceeding sixteen feet (16')" while the agency FAQ reads "13'7” and greater" (our own observation, following identically from the two texts).
TENNESSEE_ESCORT_BOUNDARY_GAPS
A houseboat priced eight times apart by two official schedules
The statute and agency website list three distinct stepped bands starting at 16' ($500, $750, $1,000), whereas the older administrative code imposes a base fee of $2,500 + $100/inch above 17'.
TDOT — OS/OW Permit Prices, Single Trip & Annual (undated) — Tennessee Department of Transportation, Traffic Operations Division — "8'6" up to 14' $20.00"; "14'1" up to 16' $30.00"; "Over 16' $30.00 + $5 for each additional foot or fraction"; "Excess Length $20.00"; "Excess Height $20.00"; "Excess Weight .06/ton mile" over "20.00+"; the bridge fee rows; the mobile home, houseboat, THP escort and annual permit rows undated document · read
TDOT — OS/OW Permits Frequently Asked Questions (undated) — Tennessee Department of Transportation, Traffic Operations Division — "Width 8'6”" / "Height 13'6”"; the escort table "10'1” – 12'6”", "12'7” – 13'6”", "13'7” and greater", "15'1” and greater", "90'1” – 120'", "120'1” and greater"; "When the width of the load exceeds 18' or the height exceeds 18' THP escorts are required ... a minimum of two (2) officers for a minimum of four (4) hours at a rate of $65.00 per hour + $.13/mile"; "Gross Vehicle Weight in excess of 165,000 pounds Width in excess of 16' Height in excess of 15'6”"; the superload processing times; "If the height of the load exceeds 15'6” and/or the width exceeds 16' a route survey will be required"; and, in the same answer, Rule 1680-07-01-.12(1)'s "super heavy" and "extra-overdimensional" definitions undated document · read
TDOT — OS/OW Permits News & Memos (undated) — Tennessee Department of Transportation, Traffic Operations Division — "01.15.26 Emergency Declaration" — the emergency and holiday restriction portal undated document · read
Tenn. Code Ann. § 55-7-201 — Length limits (via Justia — SECONDARY source) — Justia, reproducing the Tennessee Code Annotated — (b) 45 ft single unit and 65 ft for a truck-and-trailer combination; (c) the 52 ft towed vehicle and the 41 ft kingpin condition; (d) 28 ft 6 in twins; (f) 75 ft for single-length logs, poles or timber rev. · read secondary host
Tenn. Code Ann. § 55-7-202 — Width and height limits (via Justia — SECONDARY source) — Justia, reproducing the Tennessee Code Annotated — (a)(1) "exceeds eight feet (8′)"; (c) "not exceeding eight feet six inches (8′ 6″) ... over the interstate system and other federal-aid highways"; (d) "does not exceed eight feet six inches (8′ 6″)" and "does not exceed thirteen feet six inches (13′ 6″)" rev. · read secondary host
Tenn. Comp. R. & Regs. 1680-07-01-.10 — Height pole and route survey (via Cornell LII — SECONDARY source) — Cornell Legal Information Institute, reproducing the Tennessee Compilation Rules & Regulations — (1)(c) the route survey "If the height of the movement is fifteen feet (15') or more"; (1)(d) "When the permitted vehicle and load exceeds fifteen feet (15') in height, the permittee shall determine all vertical clearances by use of a front escort vehicle having protrusions equal to, at a minimum, the height of the permitted vehicle and load." rev. · read secondary host
Tenn. Comp. R. & Regs. 1680-07-01-.21 — Escort vehicle requirements (via Cornell LII — SECONDARY source) — Cornell Legal Information Institute, reproducing the Tennessee Compilation Rules & Regulations — (1)(a) "The escort vehicle must be a vehicle weighing more than 2,000 pounds with a manufacturer's gross vehicle weight rating less than 18,000 pounds and must be properly licensed." — vehicle, placard, lighting and equipment standards only; no operator certification anywhere in the section rev. · read secondary host
Tenn. Comp. R. & Regs. 1680-07-01-.24 — Permit fees, payment and refunds (via Cornell LII — SECONDARY source) — Cornell Legal Information Institute, reproducing the Tennessee Compilation Rules & Regulations — (1)(d) the houseboat "$2,500 plus $100 for each additional inch or fraction thereof greater than seventeen feet (17')"; (3)(a) the $20 plus 6¢ per ton-mile; (3)(b)(2) the heavy-duty towing 12¢ tier; (5)(b)(11) the $100 seed cotton annual; (7)(a)-(c) the payment methods and the unquantified card surcharge; (7)(d) the refund rule rev. · read secondary host
Common questions
Questions
How much is an oversize permit in Tennessee?
The single-trip base is $20, before the dimension bands, the overweight component and the transaction charge. The base alone is rarely what is paid.
When does Tennessee require a pilot car?
The first width trigger is over 10', and it varies by road class — the figure shown is the lowest across classes.
What is a superload in Tennessee?
Tennessee's published gross-weight superload line is over 165,000 lb. It is not 80,000 lb; that is the federal legal gross limit, not a superload threshold.
Do Tennessee's own documents contradict each other?
Yes, in 4 place(s) we hold both documents for. They are set out in full above, each with its pinpoint citation, and none of them has been adopted.