Arizona Oversize Load Permits, Regulations & Axle Rules

Arizona sorts permitted movement into three tiers, and which tier a load lands in sets its clock. The narrowest permitted loads, up to 10 feet wide (11 feet for self-propelled cranes and specialty equipment), up to 14'6" high, with front and rear overhangs no greater than 10 feet, within 120 feet overall, and under 250,000 lbs, are eligible for continuous 24/7 travel. That's a real advantage on long desert corridors where an overnight run avoids both midday heat and metro traffic.

Loads that exceed those continuous-travel limits but stay within 16 feet wide and 16 feet high may run on a night-and-weekend schedule: transport may begin at 3:00 AM and must wrap no later than one-half hour after sunset. The catch is that night-eligible routes are defined in the Arizona Department of Transportation (ADOT) Table 4, so not every road qualifies.

Loads wider than 16 feet or taller than 16 feet, or any load that pushes into Class C territory, are held to standard daylight: one-half hour before sunrise to one-half hour after sunset.

Six holidays halt any load over continuous-travel dimensions: New Year's Day, Memorial Day, Independence Day, Labor Day, Thanksgiving, and Christmas. The blackouts run well past the calendar date. When a holiday falls on a Friday or Saturday, permitted transport must stop by noon the preceding Thursday and cannot resume until Monday morning. A Monday or Sunday holiday cuts off at noon Friday and doesn't reopen until Tuesday. ADOT may approve a Class C exception to a holiday blackout when the movement is in the best interest of public safety.

Class C loads on certain Table 4 routes face an extra weekend restriction: no transport from noon Friday through 3:00 AM Monday regardless of the holiday calendar.

Arizona also imposes weekday metro curfews in the Phoenix and Tucson areas from 7:00 AM to 9:00 AM and 4:00 PM to 6:00 PM. On major urban routes, including sections of I-10, I-17, SR 51, SR 143, US 60, I-19, SR 77, SR 86, and SR 210, any load over 10 feet wide is barred entirely during curfew. On a second group of select loop routes (SR 24, portions of the SR 202 Loop, SR 101, and SR 989), a load between 10 and 12 feet wide may pass with a rear escort; anything over 12 feet has no transport option during those hours.

Weather stops the clock on any permitted load: visibility below 500 feet from blowing dust, snow, fog, or heavy rain; road surfaces with reduced normal traction (snow, ice, or flooding); and any load-destabilizing condition such as high winds or falling objects all require the driver to pull clear and wait it out.

Arizona does not observe Daylight Saving Time. All permit times are Mountain Standard Time year-round, except for routes crossing Navajo Nation tribal lands, which do observe DST.

Arizona's most operator-specific carve-outs apply to watercraft, houseboats near Lake Powell, and self-propelled specialty equipment.

Personal watercraft (no wider than 12 feet) moving to any of six designated lake launch areas, Alamo, Havasu, Mead, Mohave, Powell, and Saguaro, may operate on state highways within 10 miles of those sites during weekends and holidays, from one-half hour before sunrise to one-half hour after sunset, under an annual Class A watercraft permit.

Houseboats routed through the Page and Lake Powell area travel on an extended-approval Class C permit running on specific state highway segments, SR 98 and US 89 near Glen Canyon, with its own maximums: up to 16'6" wide, up to 25 feet high, up to 120 feet overall, and up to 150,000 lbs. That permit requires front and rear escort at all times; height above 17 feet adds a front height-pole escort; and any width over 14 feet requires active traffic control at the Glen Canyon Bridge, closing access from each end. Unlike general Class C loads, houseboat moves on these designated segments may run during daylight including weekends and holidays.

Self-propelled mobile cranes, drilling rigs, and similar specialty equipment get a dedicated Class A permit with a slightly looser continuous-travel threshold: up to 11 feet wide (versus 10 feet for general loads) still qualifies for 24/7 movement, and the metro curfew doesn't apply until the equipment exceeds 11 feet wide.

For length relief, Arizona allows a pole trailer hauling non-reducible poles, pipes, or structural material up to 80 feet of cargo-carrying length. Stinger-steered vehicle and boat transporters may reach 80 feet overall, that measurement excluding extendable ramps and a 4-foot front and 6-foot rear overhang allowance. Towaway trailer transporters are permitted up to 82 feet overall, and drive-away saddlemount combinations carrying up to three saddlemounted units can reach 97 feet. Vehicles hauling manufactured vehicles or fiber and forage loads get an additional overhang allowance: extensions up to 3 feet beyond the front and 6 feet beyond the rear of the bed or body are excluded from length calculations when the unit is loaded.

Natural forest products, timber, logs, pulpwood, biomass, and wood chips, may qualify for temporary relief from length restrictions and weight limits on designated state routes under a special permit with tridem axle configuration, tied to the state's Healthy Forest wildfire mitigation program.

Arizona calls its top-tier permit the Class C special permit. The state does not use the word "superload." A load earns a Class C whenever it exceeds any one of four ceilings: more than 14 feet wide, more than 16 feet high, more than 120 feet in overall length, or more than 250,000 lbs gross. Exceeding the maximum permitted axle-group weight computations under ADOT's weight tables also triggers the Class C regardless of overall gross weight.

The Class C is single-trip-only with a four-working-day validity window. Before it issues, the application goes through ADOT's Class C Unit, and average processing runs about 48 hours, but that clock doesn't start until all required documentation is in hand, and some analyses run longer.

Overweight Class C loads require an engineering analysis by ADOT's Bridge Preservation Services, reviewing every structure on the proposed route against the load's axle weights and spacings. That analysis can take up to two weeks, which is the real lead-time driver. Certified weights are mandatory; submitting incorrect weights means a second analysis and a second fee. For Class C loads failing to meet the permitted axle-group weight tables, a private engineer may prepare the analysis at $75 per 50-mile route increment, reviewed by an ADOT engineer, or ADOT can perform it directly at $125 per 50-mile increment.

Any Class C applicant must contact all utility and cable companies with lines crossing the proposed route to confirm overhead clearances. If a route survey and contingency plan is required (see Route Survey Process), that must be assembled before the permit issues as well. Where the move involves adjusting or temporarily removing any highway feature (signals, signs, delineators), an encroachment permit from ADOT is also required.

The base Class C permit fee is $15 for oversize-only loads or $75 for any overweight component. On top of that, a review fee of $15 applies when height or width is 18 feet or less; the review fee steps up to $25 when height or width exceeds 18 feet. Engineering fees are added on top and depend on route length. ADOT's published combined totals work out to $30, $40, $90, or $100 depending on whether the load is over 80,000 lbs and whether its dimensions exceed 18 feet.

Arizona does not impose a fixed dimensional or weight threshold that automatically triggers a route survey the way some states do. For Class C permits, ADOT evaluates each application individually and may require a route survey and contingency plan as a condition of approval. The department considers bridge capacities, load size and weight, pavement stress, road width and grade, and traffic dynamics on the proposed route when making that call.

When a route survey is required, it belongs to the applicant, not ADOT. The survey must document all roadway features that could inhibit movement; all obstructions subject to potential disturbance or damage; how structures, delineators, foliage, and traffic control devices will be managed or avoided; all available pullout points by highway and milepost; how side traffic will be managed through tight spots; the rate of speed along the route; approximate transit times; a breakdown contingency plan; and an estimated time to change power units if that becomes necessary. The completed survey goes to ADOT and must be on file before the permit is finalized.

Separate from the discretionary route survey, a utility notification requirement kicks in for any load exceeding 16 feet in height (or any route-specific height restriction listed in Table 4). The permittee must contact the responsible utility companies along the route to notify them of possible disturbance or damage from overhead lines.

The structural component of the review, bridge and overpass capacity analysis, is mandatory for any load exceeding 250,000 lbs or exceeding the maximum permitted axle-group weight computations, or where the load would exceed a bridge weight restriction posted in Table 4. ADOT's Bridge Preservation Services handles that, and it runs up to two weeks. Because the analysis must finish before the permit issues, heavy Class C moves effectively require the route cleared structure-by-structure before the first wheel turns.

Arizona also maintains a 35-plus-page Table 4 listing highway-specific restrictions, required conditions, and allowances for every state highway. Permittees must check ADOT's electronic permitting portal for the most current Table 4 conditions before each trip. That review is a legal obligation, not a suggestion.

Arizona's law enforcement escort requirement is fully discretionary. There are no published width, height, length, or weight thresholds that automatically require a Department of Public Safety (DPS) officer. The department may require additional traffic control by a uniformed certified law enforcement officer to ensure highway safety, decided case by case during permitting. Class C applicants should expect the department to attach a law-enforcement escort to any particularly large, heavy, or complex move. Certain routes listed in Table 4 also carry a standing law-enforcement escort condition.

The agency is the Arizona Department of Public Safety (DPS). When the permit specifies a DPS escort, the carrier must contact the DPS Escort Scheduler at least 12 hours before transport is set to begin, and that contact must happen after the permit is in hand, not before. If DPS is unavailable for a scheduled move, the permittee may substitute other uniformed certified law enforcement, provided at least one officer in the group holds current FMCSA enforcement certification. All law-enforcement escorts must operate in a fully marked patrol vehicle.

Because escort requirements are assigned during permitting rather than at fixed dimensional breakpoints, there's no simple table a carrier can consult ahead of time. The practical approach is to build the 12-hour DPS notification window into any Class C move plan from the start, and to treat a police escort as a realistic possibility on any move that pushes into Class C territory.

The codified civilian escort thresholds are narrower than in many states. During the overnight operating window (3:00 AM to one-half hour before sunrise), loads between 11 and 14 feet wide require one rear civilian escort; loads between 14 and 16 feet wide need both a front and a rear escort. A load over 15 feet high during that window requires a front escort with a height pole. For overhang, front or rear overhang exceeding 20 feet requires the corresponding directional escort regardless of time of day. Outside those codified windows, escort assignments flow from the permit conditions set by the department.