Iowa oversize and overweight rules
The short answer
Last checked
Without a permit, a load in Iowa can be up to 8 ft 6 in wide, 13 ft 6 in high and 80,000 lb gross on interstates, 80,000 lb gross with up to 5 axles on roads other than interstates, 90,000 lb gross with 6 axles on roads other than interstates or 96,000 lb gross with 7 or more axles on roads other than interstates, with the conditions in the legal limits table. A pilot car is required for loads over 14 ft 6 in wide on two-lane roads, or over 120 ft long, and a height pole car for loads over 14 ft 6 in high; the start differs on some routes or with some loads, with the conditions in the pilot car table.
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Legal limits without a permit
| Limit | Up to | Roads | Rule |
|---|---|---|---|
| Width | 8 ft 6 inHay, straw, stover and bagged bedding loads may be 12 feet 5 inches wide. | All roads | Iowa Code § 321.454(1) |
| Height | 13 ft 6 inVehicle transporters may be 14 feet, and hay, straw, stover and bagged bedding loads 14 feet 6 inches. | All roads | Iowa Code § 321.456(1) |
| Length, single truck | 45 ftFront and rear bumpers included. | All roads | Iowa Code § 321.457, paragraph a |
| Length, semitrailer | 53 ftWith a truck tractor, not counting retractable extensions supporting the load. A lowboy used only for construction equipment may be 57 feet. | All roads | Iowa Code § 321.457, paragraph f |
| Gross weight | 80,000 lbOnly off the Interstate does Iowa’s commercial vehicle table allow more. | Interstates | Iowa DOT, Permit Types, Legal Limits |
| Gross weight, 1 to 5 axles | 80,000 lbA five axle livestock vehicle may carry 86,000 pounds. | Roads other than interstates | Iowa DOT, Permit Types, Legal Limits |
| Gross weight, 6 axles | 90,000 lbFor a commercial vehicle driven by a CDL holder, with 60 feet between the extreme axles; a shorter spread gets less, and other vehicles are held to 80,000 pounds. | Roads other than interstates | Iowa DOT, Permit Types, All-Systems Overweight Permit |
| Gross weight, 7 or more axles | 96,000 lbFor a commercial vehicle driven by a CDL holder, on seven axles spread 62 feet; a shorter spread gets less, and other vehicles are held to 80,000 pounds. | Roads other than interstates | Iowa DOT, Permit Types, All-Systems Overweight Permit |
Source: Iowa Code § 321.454, Iowa Code § 321.456, Iowa Code § 321.457, Iowa DOT, Permit Types page
Axle weight limits
| Axle or group | Without a permit | With a permit | Roads |
|---|---|---|---|
| Any single axle | 20,000 lbOn pneumatic tires; 14,000 pounds on solid rubber tires. | Not set | All roads |
| 2 or more axles in a group, spread over 3 ft 4 in to 8 ft | 34,000 lbAny two or more consecutive axles more than 40 and up to 96 inches apart count as a tandem, also inside a longer group. | Not set | All roads |
| Gross weight | 80,000 lbOnly off the Interstate does Iowa’s commercial vehicle table allow more. | Not set | Interstates |
| Gross weight, 1 to 5 axles | 80,000 lbA five axle livestock vehicle may carry 86,000 pounds. | Not set | Roads other than interstates |
| Gross weight, 6 axles | 90,000 lbFor a commercial vehicle driven by a CDL holder, with 60 feet between the extreme axles; a shorter spread gets less, and other vehicles are held to 80,000 pounds. | Not set | Roads other than interstates |
| Gross weight, 7 or more axles | 96,000 lbFor a commercial vehicle driven by a CDL holder, on seven axles spread 62 feet; a shorter spread gets less, and other vehicles are held to 80,000 pounds. | Not set | Roads other than interstates |
| Single axle standing alone | Not set | 20,000 lbOnly a special or emergency move on a route Iowa DOT has reviewed, or a crane at up to 24,000 pounds an axle on a reviewed route, may carry more. | All roads |
| 2 axles in a group | Not set | 46,000 lb (24,000 lb an axle)Only the truck tractor’s tandem and the trailer’s tandem, each axle with at least four tires; any other tandem stays at 20,000 pounds an axle. | All roads |
| 3 or more axles in a group | Not set | 20,000 lb an axleEach axle of a group of three or more; the 46,000 pound tandem allowance covers only two axle groups. | All roads |
| Gross weight | Not set | Not a hard ceiling: above this, Iowa DOT issues a single trip permit only after finding the move will not unduly damage the road and serves the public interest.100,000 lb | All roads |
The Iowa rules on file give no bridge formula for this page to apply to axle groups; the axle table and its source give the group limits. “With a permit” lists the state’s permit figures; read each row’s condition, since some are review thresholds rather than limits.
Source: Iowa Code § 321.463, Iowa DOT, Permit Types page, Iowa Admin. Code r. 761-511.17
Pilot cars and escorts
Each row is one rule. A load can meet several; the permit lists the escorts for your move.
| Load | Roads | Front | Rear | Height pole | Police | |
|---|---|---|---|---|---|---|
| over 12 ft up to 14 ft 6 in wideA rear escort on a four-lane road or a front escort on a two-lane road, or in its place an amber or strobe light on the power unit and the rear of the load. The permit office may require more.The condition says what goes alongMinimum Warning Devices and Escort Requirements chart, Width | All roads | See the source | 0 | 0 | 0 | 0 |
| over 120 ft longApplies on four-lane and two-lane roads. The escort stays about 300 feet from the load. The permit office may require more escorts.Minimum Warning Devices and Escort Requirements chart, Length, over 120 feet | All roads | 1 behind | 0 | 1 | 0 | 0 |
| over 14 ft 6 in up to 20 ft highThe escort measures every vertical clearance on the route. The permit office may require more escorts.Minimum Warning Devices and Escort Requirements chart, Height, over 14 feet 6 inches up to and including 20 feet | All roads | 1 height pole car | 0 | 0 | 1 | 0 |
| over 14 ft 6 in up to 18 ft wideNo light can replace this escort. The permit office may require more escorts.Minimum Warning Devices and Escort Requirements chart, Width | Two-lane roads | 1 in front | 1 | 0 | 0 | 0 |
| over 14 ft 6 in up to 16 ft 6 in wideA rear escort, or in its place an amber or strobe light on the power unit and the rear of the load. The permit office may require more escorts.The condition says what goes alongMinimum Warning Devices and Escort Requirements chart, Width | Two or more lanes in your direction | See the source | 0 | 0 | 0 | 0 |
| over 16 ft 6 in up to 18 ft wideNo light can replace this escort. The permit office may require more escorts.Minimum Warning Devices and Escort Requirements chart, Width, over 16 feet 6 inches up to and including 18 feet | Two or more lanes in your direction | 1 behind | 0 | 1 | 0 | 0 |
- The lead pilot car is the one that carries the height pole.
When you can travel
Holidays
All special permit movement
No movement on Memorial Day, Independence Day and Labor Day, after noon on the days before them, or on holiday weekends (holiday on Fri, Sat, Sun or Mon). Movement resumes half hour before sunrise the day after. Special events with abnormally high traffic are also barred. Thanksgiving, Christmas and New Year are not listed, so no state holiday bar applies on them.
Weekends
All special permit movement
No separate weekend bar. Weekends are restricted only as part of holiday weekends and special events.
Night
All special permits
Half hour before sunrise to half hour after sunset. Night (continuous) moves are allowed up to 12 ft wide, 14 ft 6 in high and 100 ft long, at legal axle limits, on roads at least 22 ft wide with 11 ft lanes and safety lamps. The authority may allow another period for traffic volume.
Cities and rush hour
No metro curfew found in the state’s special permit rules.
Every state on one page: holiday, weekend, night and city restrictions by state. For this year’s holiday, see Thanksgiving 2026 restrictions.
Single trip permit fees
Within each kind of fee the largest that fits your load applies, and the kinds add up.
| Fee | When it applies | Amount |
|---|---|---|
| Permit feeIowa Code 321E.14(1)(e) | Every single trip permit | $35 |
| Trip registration fee761 IAC 511.5(5) | over 80,000 lb gross | Not computed here, see the source |
Source: Iowa Code 2026, 321E.14(1)(e), 761 IAC 511.5(2) and (5)
Where to apply
Iowa issues permits through Iowa Automated Permitting System (IAPS). Apply at ia.gotpermits.com.
What the rules don’t say
Where the sources are silent or say two things. Ask the state before you rely on these.
Legal limits
- In a double, each trailer may be at most 28 feet 6 inches (§ 321.457). Iowa DOT says a permit is typically required above the figures shown.
Axle weights
- Iowa Code § 321.463(6) sets three group weight tables by span and axle count, for primary highways, nonprimary highways and commercial vehicles with a CDL driver off the Interstate. They differ from the federal bridge formula, so check your groups against the right table.
- Two axles more than 8 feet apart may carry 38,000 to 40,000 pounds depending on spacing.
- The higher gross off the Interstate, 90,000 pounds on six axles and 96,000 on seven, needs a commercial vehicle with a CDL driver and the full axle spread.
- Axles less than 40 inches apart count as one axle.
- Solid rubber tires (14,000 pounds an axle), farm equipment, natural gas vehicles, idle reduction equipment, livestock haulers, borrow-site and construction haulers, tow trucks and raised retractable axles have their own rules. Registered weight also caps the load.
- The statute (§ 321.463) doesn’t state a steering axle or pounds per inch tire limit. Special mobile equipment on flotation tires may carry up to 36,000 pounds on a single axle.
- Annual, raw forest product, multitrip, emergency Interstate, fluid milk, small crane and all-systems overweight permits each have their own limits.
- The 46,000 pound permit tandem covers only the truck tractor’s tandem and one trailer tandem, each axle with at least four tires, not part of a larger group.
- Iowa DOT may authorize heavier axle, group and gross weights for a special or emergency move on a reviewed route.
- Iowa Code doesn’t state a statewide seasonal limit; Iowa DOT and local authorities post embargoed roads and bridges, so check postings.
Pilot cars and superloads
- Iowa’s chapter 511 rules don’t define a superload. The permit office sets conditions for loads beyond its escort chart.
- The chart stops at 18 feet wide and 20 feet high; larger loads are permitted case by case, and the permit office may require more escorts.
- From 12 to 16 feet 6 inches wide, an amber or strobe light on the power unit and rear of the load can replace the escort, except over 14 feet 6 inches on a two-lane road.
- The chart splits four-lane and two-lane roads; it doesn’t address three-lane roads.
- Long front or rear projections and weights over 80,000 pounds call for lights or flags, not escorts.
- Each load needs its own escort, and escorts may not stop traffic; contact an on-duty peace officer for traffic control. The rule doesn’t state a police escort line.
Permit fees
- A truck not registered for the combined weight of truck and load also pays $4 for each ton over 40 tons. The rule doesn’t state how a part ton is rounded.
- The $35 covers a single or round trip.
- The cost of removing and replacing obstructions or signs, and of protecting structures and bridges, is charged at cost. Escorts, tree trimming and city and county permits are extra.
- The current fee rule took effect July 15, 2026; confirm fees with Iowa DOT before quoting.
Questions about Iowa
- When do I need an oversize permit in Iowa?
- Without a permit, a load in Iowa can be up to 8 ft 6 in wide, 13 ft 6 in high and 80,000 lb gross on interstates, 80,000 lb gross with up to 5 axles on roads other than interstates, 90,000 lb gross with 6 axles on roads other than interstates or 96,000 lb gross with 7 or more axles on roads other than interstates, with the conditions in the legal limits table. Loads past these figures generally need a permit from the state; see the legal limits table for the exceptions and for length, which depends on the vehicle.
- How much does an Iowa oversize permit cost?
- On the fee schedule we checked, a single trip permit starts at $35. Some charges are not computed here; the fee table names them. The estimator on this page adds up the fees for your load.
- When do you need a pilot car in Iowa?
- A pilot car is required for loads over 14 ft 6 in wide on two-lane roads, or over 120 ft long, and a height pole car for loads over 14 ft 6 in high; the start differs on some routes or with some loads, with the conditions in the pilot car table. How many cars, and whether they lead or follow, depends on the road; the pilot car table lists each rule.
- When can oversize loads travel in Iowa?
- At night: Half hour before sunrise to half hour after sunset. Night (continuous) moves are allowed up to 12 ft wide, 14 ft 6 in high and 100 ft long, at legal axle limits, on roads at least 22 ft wide with 11 ft lanes and safety lamps. The authority may allow another period for traffic volume. On weekends: No separate weekend bar. Weekends are restricted only as part of holiday weekends and special events.
- Can oversize loads move on holidays in Iowa?
- No movement on Memorial Day, Independence Day and Labor Day, after noon on the days before them, or on holiday weekends (holiday on Fri, Sat, Sun or Mon). Movement resumes half hour before sunrise the day after. Special events with abnormally high traffic are also barred. Thanksgiving, Christmas and New Year are not listed, so no state holiday bar applies on them.
Sources
- Iowa DOT Oversize/Overweight Permit TypesIowa DOT, Single Trip Oversize/Overweight Permit TypesIowa Department of Transportation. Read .
- Iowa Code § 321.454: Width of vehiclesIowa Code § 321.454Iowa Legislature. Read .
- Iowa Code § 321.456: Height of vehiclesIowa Code § 321.456Iowa Legislature. Read .
- Iowa Code § 321.457: Maximum lengthIowa Code § 321.457Iowa Legislature. Read .
- Iowa DOT, Oversize/Overweight Permit RequirementsIowa DOT, Oversize/Overweight Permit RequirementsIowa Department of Transportation. Read .
- Iowa Code § 321.463: Maximum gross weight, exceptions, penaltiesIowa Code § 321.463Iowa Legislature, Legislative Services Agency. Read .
- Iowa Code § 321.1: Definitions of words and phrasesIowa Code § 321.1(80)Iowa Legislature, Legislative Services Agency. Read .
- Iowa Administrative Code 761, rule 511.17: Maximum axle weights and maximum gross weights for vehicles and loads moved under permitIowa Admin. Code r. 761-511.17Iowa Department of Transportation (rule); published by the Iowa Legislature, Iowa Administrative Code. Read .
- Iowa Administrative Code 761, chapter 511, Special Permits for Operation and Movement of Vehicles and Loads of Excess Size and Weight, rule 511.19(321E) EscortingIowa Admin. Code r. 761-511.19(321E)Iowa Department of Transportation (rule); published by the Iowa Legislature, Iowa Administrative Code. Read .
- Iowa Code 321E.14, Fees for permitsIowa Code 2026, 321E.14(1)(e)Iowa Legislature. Read .
- 761 Iowa Administrative Code 511.5, Fees and costs761 IAC 511.5(2) and (5)Iowa Department of Transportation (Iowa Legislature, Iowa Administrative Code). Read .
- Iowa Department of Transportation page naming the permit systemIowa Department of Transportation, permit system pageIowa Department of Transportation. Read .
Found something wrong or out of date? Report an error to hello@thirteensix.com.
This page is a dated summary in our own words, not legal advice. The permit the state issues governs your move, and states change their rules; check with Iowa before you travel.
Bordering states
- Crossing into Illinois? See Illinois rules
- Minnesota, coming soon
- Crossing into Missouri? See Missouri rules
- Nebraska, coming soon
- South Dakota, coming soon
- Wisconsin, coming soon
More guides: all states and the rules library.
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