A superload is a vehicle or combination with a non-divisible load exceeding sixteen feet wide, sixteen feet high, 125 feet of load length, or 200,000 pounds.

Follow these steps to receive a permit for a superload:

  1. Applications for loads over 200,000 pounds must be submitted in writing and received at least 30 days before the proposed date of movement (RCW 46.44.091)(5)). You must submit applications for loads over sixteen feet wide or sixteen feet high in writing at least seven (7) calendar days before the proposed date of movement. You may ask for a Request for Approval of Oversize/Overweight Movement (Form 560-022) from Commercial Vehicle Services.
  2. The motor carrier or shipper must provide the following information to Commercial Vehicle Services (WAC 468-38-405 Superload Movement Criteria):
    • Evidence describing the movement's purpose and whether the move is necessary (and in the public interest). Written certification by military officials or officials of public or private power facilities that the movement is required must also be included when appropriate;
    • You must clearly show that the item you are transporting is non-divisible. You must provide a sketch or photograph of the item with an explanation of why it cannot be shipped in parts;
    • A sketch of the transporting laden vehicle showing axle loadings, axle spacings, tire sizes, tires per axle, width and height;
    • If the load can be barged, shipped by rail for all or part of the route, the shipper must review those alternatives. If the applicant wants to show that "it is not reasonable for economic or operational considerations" to ship it by water or rail, the applicant must present whatever data is needed to support that judgment;
    • The applicant must propose a route that they know is adequate to accommodate the laden vehicle's width and height and appears sufficient to support the weight of the vehicle and load. Usually, the pilot car operators who specialize in over-dimensional movements request this information.
    • If the route includes county roads or city streets, the applicant must show that permits from each of those jurisdictions will be issued. The written request will describe at what point they will use these county roads or city streets, the name or number of the road or street and the county or city official who has approved the proposed move using its roads or streets; and
    • A traffic control plan depicting the route and specific procedures that will be followed to control traffic-flow along the route, including:
      • Estimated traffic delays
      • Lane restriction
      • Use of escort vehicles and flag persons
      • Movement of overhead obstacles
      • Railroad schedules* for crossings
      • Provisions for emergency vehicles to navigate around the load

*Note: Physical examination of all railroad crossings by the carrier or designee is critical. A lack of sufficient ground clearance can be fatal.

  1. WSDOT will initiate an analysis of bridges and pavement if WSDOT determines the movement is necessary. If the analysis requires significant time by the WSDOT staff, the applicant may be asked to share in those costs.
  2. If the structures, clearances and pavements are judged adequate, the permit will be issued or will be further negotiated to define its terms (escort requirements, hours of movement, etc.)


166,800 electric vehicle

registrations in Washington in 2023, up from 114,600 in 2022.

87 wetland compensation sites

actively monitored on 918 acres in 2023.

25,000 safe animal crossings

in the Snoqualmie Pass East Project area since 2014.