Wisconsin Oversize Load Permits, Regulations & Axle Rules

Wisconsin splits permitted loads into two tiers before any travel rule applies, and which tier a load lands in is the first order of business.

A purely overweight load, one that exceeds 80,000 lbs but stays within legal size, faces no travel-time restrictions at all. It can run around the clock, on weekends, and through restricted-travel holidays without limitation.

Everything changes once the load also becomes oversize. Loads that exceed 12' wide, 13'6" high, or 150' long are locked out of darkness entirely: no travel during hours of darkness at any time of week. On weekends, this tier halts completely from noon Saturday until sunrise Sunday, plus again from 4:00 PM to 8:00 PM Sunday. Holidays pull the same noon-to-sunrise window, from noon on the eve of each restricted-travel holiday until sunrise the morning after. Wisconsin's restricted-travel holiday list is longer than most states' and includes entries that catch carriers off guard: alongside New Year's Day, Easter weekend, Memorial Day, Independence Day, Labor Day, Thanksgiving weekend, Christmas Eve, Christmas Day, and New Year's Eve, it also includes the opening Saturday and Sunday of Wisconsin's gun deer hunting season (typically mid-November, set annually by the DNR). Around Thanksgiving, the blackout adds two extra restricted days beyond the holiday window. The stretch from Christmas Eve through New Year's Day stacks four consecutive restricted periods and can shut down movements for the better part of two weeks.

Loads that are oversize but stay within 12' wide, 13'6" high, and 150' long face a lighter version: no restrictions statewide except in Columbia, Dane, Milwaukee, Rock, and Waukesha counties, where no oversize load may move from 4:00 PM to 8:00 PM on Sundays, on Fridays from the fourth Friday in May through Labor Day, on restricted-travel holidays, and on the day before each holiday.

Two local curfews apply to all permitted oversize loads regardless of dimensions. On the Milwaukee County Expressway system, no oversize movement is permitted Monday through Thursday from 6:00 AM to 9:00 AM or 3:00 PM to 6:00 PM, on Fridays from 6:00 AM to 9:00 AM, or on Fridays and Sundays from 3:00 PM to 8:00 PM. Separately, the Madison Beltline (US-12/US-18 between Verona Road and Stoughton Road) bars oversize loads Monday through Friday from 6:00 AM to 9:00 AM and 3:00 PM to 6:00 PM. The Milwaukee County Expressway also imposes a hard dimension cap: no permit exceeding 14' wide, 14'6" high, or 150' long is valid on that system (with exceptions for I-41 between W Florist Ave and W Hampton Ave, and I-94 between the Waukesha County line and WI-100).

Additional operating rules: loads 16' or wider are capped at 35 mph on any highway without paved shoulders; drivers must maintain at least 1,000' of following distance; and permits are voided by adverse weather (fog, smoke, heavy rain, snow, ice, or dangerous winds). Wisconsin does not provide for continuous 24-hour movement for any oversize load type, and there are no additional city-specific rush-hour curfews beyond the Milwaukee Expressway and Madison Beltline rules.

Wisconsin gives several commodity classes dimensions or movement rules that differ materially from general oversize standards.

Implements of husbandry receive broad exemptions: no width or height restriction applies, and length is allowed up to 60' for a single vehicle or 100' for a two-vehicle combination (with no limit for irrigation systems). They are subject only to lighting and marking requirements.

Automobile haulaways may be up to 66' long as a vehicle, with an additional 4' front overhang and 5' rear overhang, giving an effective overall reach of 75'.

Poles, pipe, and girders for pipeline companies, public utilities, municipal utilities, and cooperatives may be up to 60' on a single vehicle or 120' on a two-vehicle combination without a permit, plus a load extending up to 10' beyond the front bumper, and may be up to 9' wide without a permit on non-interstate roads.

Livestock combinations are allowed up to 75' overall when the trailer is designed and primarily used for transporting livestock, with the trailer itself limited to 53'.

Sealed international trade loads (CS permit) cover cargo at 80,001 to 90,000 lbs with a minimum of six axles and a tamper-evident seal from the point of initial loading.

Wisconsin also maintains a Frozen Road Declaration program that temporarily raises weight limits on eligible routes during winter for specific commodities (forest products cut crosswise, not woodchips, plus abrasives, and salt for highway winter maintenance) up to 98,000 lbs GVW and 23,000 lbs per single axle. These elevated weights apply on state and US-numbered highways but are prohibited on the interstate system except the I-39 and I-41 corridors, and are not valid on weight-posted or local roads.

Wisconsin calls its top-tier movement a Mega Load, spelled as two words in WisDOT documentation, and the thresholds that define one are substantially higher than typical superload definitions elsewhere. A move becomes a Mega Load when it meets or exceeds any one of four criteria: 400,000 lbs gross vehicle weight or 40,000 lbs on one or more axle lines; 22' wide; 19' high; or 220' overall length. Loads below these numbers, even at 21'11" wide or 399,000 lbs, are handled through standard permitting with escalating conditions rather than the Mega Load process.

The Mega Load pathway is structured and sequential, with fixed deadlines working backward from the move date. For a standard move crossing more than one WisDOT region, the carrier must request a preliminary meeting with WisDOT at least 60 days before the intended move. The preliminary proposal (which must include photos front, rear, side, and aerial, scaled diagrams showing all dimensions and weights, tire counts and PSI, ground clearance, and carrier contact information) is due at least 30 days out. WisDOT provides preliminary approval within 10 days of receiving the proposal. A route survey must be submitted at least 14 days before the move, and WisDOT provides final approval within 7 days of receiving it. For a local move entirely within a single WisDOT region, the timelines compress: preliminary proposal 14 days out, preliminary approval within 4 days, route survey 7 days out, final approval within 3 days of survey.

Documentation requirements are extensive. The load must pass a NAS Level 7 inspection verifying weight and dimensions. Out-of-state loads must either provide proof of a NAS Level 1 MCSAP inspection or identify an approved inspection location within 25 miles of the Wisconsin entry point. If gross weight exceeds 500,000 lbs, the carrier must have a second power unit capable of continuing transport to a safe layover if the primary unit fails.

Night movement and weekend or Friday operation are not the default for Mega Loads; they require a separate written request to WisDOT. Utility coordination is mandatory for any private utility with less than 3" of vertical clearance from the load height, and proof of that coordination must accompany the route survey. Traffic impediments including monotubes, roundabouts, and railroad crossings must be mapped with detailed navigation plans. All planned layover locations must be identified, and private property layovers require written permission from the landowner.

WisDOT reviews and approves all Mega Load applications through its motor carrier services section in coordination with the relevant State Patrol region commander and region engineer. There is no intermediate tier between standard permitting and Mega Load in Wisconsin. The gap between a general permit load (say, 350' long, 21' wide) and the Mega Load threshold is handled by WisDOT imposing increasingly detailed conditions on the standard permit, but the formal Mega Load process only activates at the thresholds above.

Wisconsin places the primary route-evaluation burden on the carrier for all permitted moves, not just Mega Loads. As a condition of every single-trip permit, the permittee must evaluate the route before the move begins and confirm that the load will legally clear all vertical and horizontal obstructions, that necessary maneuvers can be completed without damaging property or causing traffic delays, and that all rules of the road will be observed. This self-survey obligation is not triggered by a specific dimension threshold. It applies to every permitted move.

For overheight loads specifically, the carrier must give prior notice to the owners of overhead wires, cables, and other facilities along the route that may be affected. The sources do not specify a height figure that activates this utility-notification duty. It attaches to any permitted overheight move.

On the administrative side, WisDOT may impose a district route review ($10 per district) when the size or weight of the vehicle and load requires review by a regional highway office, and a structure review ($10 per review) when gross weight requires analysis of specific highway structures. These reviews are imposed as permit conditions rather than triggered by fixed published thresholds.

The Mega Load route survey is a formal, mandatory document, not a carrier self-certification, and must be submitted to WisDOT at least 14 days before the move (7 days for a local move). It must be accompanied by a map or aerial image identifying all traffic impediments and mitigation plans, all private utilities with less than 3" of vertical clearance from the load height (with proof of coordination), and all planned layover locations with permission documentation. A completed Mega Load route survey is valid for 30 days. No Mega Load permit issues without it.

An additional structural constraint applies to any load over 100' overall: no permit may issue when the rear supporting axle is at or near the rear of the load unless that rear support is independently steered.

Wisconsin's escort requirements are set by a combined width-and-length matrix published by WisDOT, not by width alone, and the practical effect is that two oversize dimensions working together can demand more escorts than either would alone. The matrix works as follows.

For width alone (when length is 110' or less): no escorts up to 15' wide. From 15'1" to 18' wide, one private escort. From 18'1" to 20' wide, one private escort plus one Wisconsin State Patrol officer. Wider than 20', two private escorts and two State Patrol officers.

For length alone (when width is 12' or less): no escorts up to 140'. From 140'1" to 160', one private escort. From 160'1" to 200', two private escorts. Over 200', two private escorts plus one State Patrol officer.

For combined oversize in both dimensions: a load wider than 12' and longer than 110' that would require no escort on either dimension alone picks up one private escort from the combination. A load wider than 15' and longer than 110' escalates to two private escorts, even though a 15'1"-wide load that is 110' or shorter only needs one. These combined triggers are encoded in the permit system and evaluated alongside the standalone thresholds.

Height adds a separate layer: any load taller than 16' requires a pole vehicle, a front private escort carrying a height-measurement pole, in addition to whatever the width-and-length matrix requires. The total number of private escorts including the pole vehicle is capped at two.

Weight adds another: any permitted load over 350,000 lbs requires one Wisconsin State Patrol officer regardless of dimensions.

The Wisconsin State Patrol (WSP), a division of the Wisconsin Department of Transportation operating as the Division of State Patrol (DSP), is the law enforcement agency that provides police escorts. Carriers do not arrange State Patrol escorts independently. Requests must be submitted to the appropriate State Patrol region commander at least 48 hours in advance. If more than two squads are needed, 72 hours' advance notice is required. Canceling a scheduled escort with less than 24 hours' notice triggers a $100 surcharge. State Patrol escort fees are calculated on actual cost: duty hours at the officer's pay rate, vehicle mileage, and applicable meal and lodging allowances.

Except for the fixed breakpoints in the width-and-length matrix and the weight and height triggers above, law enforcement escort can also be imposed as a condition of any permit at the issuing authority's discretion, for example on unusually winding or hilly routes or in heavy-traffic areas. There is no single published dimension or weight figure that mandates police escorts for general permitted moves below the codified thresholds; decisions below those thresholds rest with the permit issuer.

Mega Load moves require two to four State Patrol squads as a baseline, with carriers responsible for supplying communication devices to all squads and private escorts for the move.

No permit requires interstate-specific law enforcement; the escort chart applies uniformly across road types, with road type affecting only escort positioning (escorts precede the load on two-way undivided roads; on one-way roads and divided highways they follow at 300 to 500').