New Hampshire Oversize Load Permits, Regulations & Axle Rules

New Hampshire applies a daylight rule to oversize permitted loads, the window between 30 minutes before sunrise and 30 minutes after sunset. Weekends are off limits entirely: no oversize permit is valid on a Saturday or Sunday unless the load qualifies as a supermove. Supermoves may travel on weekends, but only within the date and time window the permit specifies.

The state restricts oversize movement on ten holidays: New Year's Day, Martin Luther King Jr. Civil Rights Day, Washington's Birthday (Presidents' Day), Memorial Day, Independence Day, Labor Day, Columbus Day, Veterans Day, Thanksgiving Day and the day after, and Christmas Day. When a holiday falls on Saturday, the preceding Friday is added to the blackout; when it falls on Sunday, the following Monday is added. Carriers clearing multiple legs across a holiday weekend should account for the 10-holiday count. It's higher than most states and catches some dates that are ordinary workdays elsewhere, including Columbus Day and Veterans Day.

Overweight-only loads at normal traffic speeds face none of these restrictions: no daylight window, no weekend ban, no holiday prohibition.

Inclement weather stops all permitted movement regardless of load type. Any driver already in motion when weather turns must exit at the first available location and wait until conditions allow safe travel. The rules don't specify a minimum visibility distance, only "inclement weather" as the standard. Convoy operations are prohibited for all load types: each permitted vehicle travels independently. New Hampshire imposes no rush-hour curfews for any city or metro area.

New Hampshire's most detailed commodity provisions cover poles, logs, timbers, and automobile transporters.

Poles, logs, timbers, and metal are exempt from all length limits under state law, provided the load is not readily divisible and any overhang does not interfere with steering. There's no separate rear overhang cap for these commodities: the exemption extends to however far the load projects. Automobile transporters get explicit overhang allowances: a conventional combination runs up to 65 feet overall, not counting up to 3 feet of front overhang and 4 feet of rear overhang. Stinger-steered combinations go up to 75 feet overall with the same front and rear overhang exclusions. Emergency fire-fighting vehicles are also exempt from length limits. New Hampshire additionally recognizes New England Transportation Consortium (NETC) regional permits: carriers operating in compliance with a valid NETC agreement need no separate New Hampshire permit.

New Hampshire calls this tier a Supermove. A load enters supermove status the moment it exceeds any one of four thresholds: width greater than 15 feet, length greater than 110 feet, height greater than 13'6", or gross weight greater than 149,999 lbs (in practice, 150,000 lbs and above). Because the single-trip permit caps are exactly those numbers (15 feet wide, 110 feet long, 13'6" high, 149,999 lbs), there's no routine oversize single-trip overheight permit at all in New Hampshire; any load taller than 13'6" is automatically a supermove.

The supermove process is built around three mandatory deliverables, all at the applicant's expense. First, a written engineering inspection report from a professional engineer licensed in New Hampshire certifying that the hauling vehicle and equipment are adequate, that pavements and all bridge structures along the entire route can support the load without damage, and that adequate vertical and horizontal clearances and turning paths exist for the full route. Second, a confirmation from the applicable turnpike or highway district engineer, the Bureau of Bridge Design, or their designees, independently verifying that the proposed route meets the same structural and clearance criteria. Third, a physical route survey identifying minimum clearances at every point along the route.

The permit office issues the supermove permit for a specific date and time rather than a multi-day window. That date and time may be any day of the week, weekday or weekend, and any time of day or night, based on when the move can be safely carried out. This is the one load type that can lawfully run outside the standard daylight and weekday rules. Annual permits are unavailable for supermoves. Additional escort requirements beyond the baseline rules may be imposed by the permit office depending on the route and load.

New Hampshire's route survey requirement applies to two groups: any standard permitted load where height exceeds 13'6" or overall length exceeds 110 feet, and all supermoves. The permit office may also require a survey for any load when it determines the proposed route poses a potential clearance problem, regardless of dimensions.

The carrier, not the state, completes the survey. NHDOT's permit system generates a route survey form based on the load information and proposed route the applicant enters; the applicant downloads it, physically drives the route, and uploads the completed form with the application. The submission is made under penalty of unsworn falsification, meaning it carries the legal weight of a sworn statement that the route has been physically traveled and the vehicle and load can safely complete the trip at the dimensions provided. The completed survey must document obstructions, dimensional conflicts, special driving directions, lanes of travel, required speeds, and any traffic control requirements. A survey may be reused by the same carrier for the same load criteria and same route for up to 30 days before a fresh survey is required.

For loads that don't rise to a full supermove, the permit office may require either a bridge review completed by the department or a self-certification by the applicant, a written statement that the applicant has reviewed all state bridges on the proposed route and finds them adequate to carry the load without limitations or special conditions. The supermove tier removes that choice: all three elements (PE inspection report, district engineer confirmation, and physical route survey) are mandatory before the permit can issue.

New Hampshire draws a clear, codified line between civilian non-police escorts and law-enforcement escorts from the New Hampshire State Police, and the breakpoints are specific enough that a carrier can calculate the requirement from the load sheet.

Civilian non-police escorts are required when width reaches 12 feet or more (but stays at or below 14 feet), when overall length reaches 90 feet or more, when height exceeds 14 feet, or when front or rear overhang reaches 15 feet or more. A second non-police escort is added when rear overhang reaches 15 feet or more and width simultaneously reaches 12 feet or more. That's a combined trigger: both conditions must be present at once to require the second unit. The rules cap non-police escorts at two.

State Police enter at three fixed thresholds. A load 100 feet or more in overall length requires one state police escort in addition to any civilian escorts already assigned, though the State Police retain authority to waive this if they determine weather, visibility, traffic flow, or other conditions don't compromise safe movement. A load more than 14 feet wide requires a total of two state police escorts, counting any already required for length. If the move requires closure of a highway or portion of a highway, the total state police requirement rises to three, again counting any already required for other dimensions. State Police escorts are always in addition to, not instead of, required civilian escorts.

On undivided two-lane roads, a single escort leads from the front. On divided multi-lane roads, a single escort trails from the rear. When two escorts are required, one leads and one follows. At bridge crossings on two-way highways where the bridge is 24 feet or less in width, the police escort must stop all traffic in both directions while the load is on the bridge. When seven or more vehicles accumulate behind a permitted move, the permitted vehicle and escorts must yield at the nearest safe location to let them pass.

The permit office arranges any required state police escort coordination. Because the permit specifies the date and time of movement, scheduling runs through the permitting process before the move date.