New Hampshire Weigh Stations and Commercial Vehicle Enforcement

Commercial vehicle enforcement in New Hampshire is managed by the Department of Safety, Division of State Police, specifically the State Police Troop G. Unlike many Western states, New Hampshire does not have permanent weigh stations on every interstate entrance. Instead, the state utilizes a mix of permanent facilities, such as the North Hampton and Windham scales, and mobile enforcement units equipped with portable scales. These units target common freight corridors including I-93, I-95, and I-89 to ensure compliance with weight, size, and safety regulations. Carriers must adhere to the 80,000-pound gross vehicle weight limit on interstates unless they possess specific state-issued permits for divisible or non-divisible loads. Operating efficiently through New Hampshire requires staying compliant with these varying enforcement points. DispatchTool helps drivers navigate these requirements by providing truck-safe routing that accounts for specific bridge weight limits and state-recognized truck routes. By integrating route planning with real-time updates, the platform ensures dispatchers and owner-operators can avoid restricted roads and plan for potential delays at high-volume inspection sites. Create a DispatchTool account to streamline your New Hampshire route planning and compliance documentation.

Permanent Scale Locations and Operation

The two primary permanent weigh station locations in New Hampshire are located in North Hampton on I-95 South and in Windham on I-93 North. The North Hampton facility is a high-volume site due to its proximity to the Massachusetts border, often seeing over 500 trucks per day. The Windham scale serves as the primary enforcement point for northbound traffic emerging from the Boston metropolitan area. These stations are not open 24/7; instead, they operate on a randomized schedule determined by Troop G. When the 'Trucks Must Enter' signs are flashing, all commercial vehicles with a GVWR over 10,000 pounds are legally required to pull in for inspection.

Mobile Enforcement and Portable Scales

New Hampshire relies heavily on mobile enforcement teams that utilize 'Weigh-in-Motion' (WIM) technology and portable scales. According to the New Hampshire Department of Safety, mobile units frequently set up at rest areas or large turnouts on I-89 near Lebanon and I-93 near Canterbury. These units target secondary highways as well, such as Route 101 and Route 4, where bypass traffic may attempt to avoid permanent scales. Officers have the authority to direct any commercial vehicle to a level surface to conduct a weighing, and refusal to comply can result in immediate out-of-service orders and criminal charges under RSA 266:72.

Bypass Programs and PrePass Integration

New Hampshire participates in the PrePass bypass system at its major permanent facilities. As of 2024, the Windham and North Hampton scales are equipped with PrePass transponder readers. This allows carriers with a high safety score, typically an ISS (Inspection Selection System) score below 75, to bypass the scales without stopping. According to PrePass data, this saves an average of 6 to 8 minutes per bypass and approximately 0.4 gallons of fuel. Drivers must still look for the in-cab signal; a green light indicates a bypass, while a red light requires the driver to pull into the station regardless of their credentials.

New Hampshire Weight and Size Limits

Standard weight limits in New Hampshire are governed by RSA 266:18. On the Interstate Highway System, the maximum gross weight is 80,000 pounds, with axle limits set at 20,000 pounds for single axles and 34,000 pounds for tandems. On non-interstate highways, the state allows for higher limits for certain configurations, potentially up to 99,000 pounds for a six-axle combination, provided the vehicle meets the bridge formula requirements. Bridge laws in New Hampshire are strictly enforced, particularly on older spans along Route 1 and Route 3, where weight limits may drop as low as 6 tons for specific structures.

Fines and Penalties for Overweight Violations

Overweight fines in New Hampshire are calculated on a sliding scale based on the number of pounds over the legal limit. Per RSA 266:25, a vehicle exceeding its limit by less than 2,000 pounds may face a fine of approximately $100. However, for significant violations exceeding 10,000 pounds over the limit, fines increase to $0.02 to $0.10 per pound, often resulting in penalties exceeding $2,000 for a single occurrence. Additionally, the vehicle is usually grounded until the excess load is shifted or offloaded, which can lead to significant towing and storage fees from third-party vendors.

Safety Inspections and North American Standard

Troop G officers conduct Level I, II, and III inspections following the Commercial Vehicle Safety Alliance (CVSA) guidelines. A Level I inspection is the most comprehensive, covering both the driver's credentials and the vehicle's mechanical state, including brakes, fuel systems, and cargo securement. Data from the FMCSA's Analysis & Information Online indicates that New Hampshire conducts roughly 5,000 to 7,000 roadside inspections annually. Carriers should ensure that their ELD (Electronic Logging Device) data is readily transferable and that all annual inspection stickers are current to minimize time spent at the scale.

Sources

New Hampshire Department of Safety - Troop G (2024) — https://www.nhsp.dos.nh.gov/our-organization/field-operations-bureau/troop-g New Hampshire Statutes RSA 266:18 (Weight) (2024) — https://www.gencourt.state.nh.us/rsa/html/xxi/266/266-18.htm FMCSA Safety Measurement System (SMS) (2025) — https://ai.fmcsa.dot.gov/sms/

Frequently asked

Do I have to stop at New Hampshire scales if I am empty?

Yes, all commercial vehicles with a GVWR over 10,000 pounds must enter the weigh station if the signs are flashing, regardless of whether the trailer is loaded or empty. Failure to do so is a violation of NH RSA 266:72.

What is the maximum height for trucks in New Hampshire?

The maximum legal height for a commercial vehicle in New Hampshire is 13 feet 6 inches. Anything exceeding this height requires a special over-dimensional permit from the NH DOT Bureau of Turnpikes.

How much does a New Hampshire overweight permit cost?

Single-trip overweight permits typically start at $25, but the price increases based on the weight and distance traveled. Annual permits for specific divisible loads can cost upwards of $400 depending on the commodity.

Does New Hampshire use Drivewyze for bypass?

As of early 2025, New Hampshire primarily supports PrePass at its permanent facilities. Drivers using Drivewyze should monitor their application for site-specific availability, as mobile sites often do not support electronic bypass.