States have granted exemptions to several types of vehicles and basic products to operate above the standard federal limits on truck size and weight. These exemptions usually only apply to roads that are not interstates, but this is not always the case. In addition, some exemptions or higher weights are allowed through specific permissions. To summarize the prevalence of exemptions in non-interstate areas, including segments of the NHS, Figure 7 below shows the most common exemptions for commodities and vehicles that are granted by state law and the number of states in which they are present (including the District of Columbia).A permit provides a higher GVW that varies depending on the vehicle configuration for contractors and transportation companies operating within a 25-mile aerial radius of a specific construction project.
The above weight limits for special permits may be exceeded for permits issued to vehicles with tires of a certain diameter156 or for vehicles whose movement determines that it is necessary to move through the Department of Transportation (Washington). The secretary can also issue permits to operate combinations of vehicles on a route designated by the secretary between a Kansas Toll Highway Authority toll booth and a motor cargo truck terminal located 10 miles from that toll booth, or 20 miles from a toll booth on the northeast end of the turnpike (Kansas). Except for a few places near sensitive federal structures, a truck restriction means that the street is closed to truck traffic, but open to trucks that deliver locally. The Director of Transportation is authorized to issue permits to operate on state highways for a vehicle, a combination of vehicles, self-propelled agricultural or construction equipment, or special mobile equipment that exceeds state limits in size and weight. The Mississippi Transportation Commission is authorized to issue special permits for the movement of a vehicle or combination of vehicles that exceed state weight limits.
State law authorizes city officials to issue special construction permits for vehicles used in public road construction projects, U. S. government projects, or private road construction. These permits may be issued for a single trip or for continuous operation and may prescribe route, speed, or other restrictions (Hawaii Rev.).This exemption does not extend to trucks owned by counties, cities, and other political subdivisions specifically designed, equipped, and used for garbage, garbage, or solid waste disposal operations (Kan).
With respect to trucks operating in Connecticut's NHS, several provisions of state law allow trucks to exceed some elements of federal limits. The gross weight of vehicles in normal operation (operating without a special permit) is governed by state axle limits, state gross weight limits for the number of axles of a vehicle or combination of vehicles, and the state bridge formula, which is adopted from the FBF, for interstate travel (S.). The public utility commission may issue a special permit authorizing the applicant to operate or move a vehicle or combination of vehicles of a size, weight or load that exceeds the state maximum weight limits on multiple or continuous trips on any road in the State (W.).With respect to trucks operating in Montana's NHS, several provisions of state law allow trucks to exceed some elements of federal limits. The Idaho Transportation Board is authorized to issue a special permit to the owner or operator of any oversized or overweight vehicle to be transported or transported on roads and bridges.
Permits must indicate specific routes for travel and be designated as an annual or one-trip operation; they may also include other restrictions or limitations. Footnote 1 The laws in these states prohibit traveling in open parts of a vehicle that are not designed for passengers, although they do not specifically mention the cargo area of a van.