Special permits may not be issued for movements on any state highway outside the limits of any city or town in excess of the following widths:
On two-lane highways, fourteen feet;
On multiple-lane highways where a physical barrier serving as a median divider separates opposing traffic lanes, twenty feet;
On multiple-lane highways without a physical barrier serving as a median divider, thirty-two feet.
These limits apply except under the following conditions:
(1) In the case of buildings, the limitations referred to in this section for movement on any two lane state highway other than the national system of interstate and defense highways may be exceeded under the following conditions: (a) Controlled vehicular traffic shall be maintained in one direction at all times; (b) the maximum distance of movement shall not exceed five miles; additional contiguous permits shall not be issued to exceed the five-mile limit: PROVIDED, That when the department of transportation determines a hardship would result, this limitation may be exceeded upon approval of the department of transportation; (c) prior to issuing a permit a qualified transportation department employee shall make a visual inspection of the building and route involved determining that the conditions listed herein shall be complied with and that structures or overhead obstructions may be cleared or moved in order to maintain a constant and uninterrupted movement of the building; (d) special escort or other precautions may be imposed to assure movement is made under the safest possible conditions, and the Washington state patrol shall be advised when and where the movement is to be made;
(2) Permits may be issued for widths of vehicles in excess of the preceding limitations on highways or sections of highways which have been designed and constructed for width in excess of such limitations;
(3) Permits may be issued for vehicles with a total outside width, including the load, of nine feet or less when the vehicle is equipped with a mechanism designed to cover the load pursuant to RCW 46.61.655
(4) These limitations may be rescinded when certification is made by military officials, or by officials of public or private power facilities, or when in the opinion of the department of transportation the movement or action is a necessary movement or action: PROVIDED FURTHER, That in the judgment of the department of transportation the structures and highway surfaces on the routes involved are capable of sustaining widths in excess of such limitation;
(5) These limitations shall not apply to movement during daylight hours on any two lane state highway where the gross weight, including load, does not exceed eighty thousand pounds and the overall width of load does not exceed sixteen feet: PROVIDED, That the minimum and maximum speed of such movements, prescribed routes of such movements, the times of such movements, limitation upon frequency of trips (which limitation shall be not less than one per week), and conditions to assure safety of traffic may be prescribed by the department of transportation or local authority issuing such special permit.
The applicant for any special permit shall specifically describe the vehicle or vehicles and load to be operated or moved and the particular state highways for which permit to operate is requested and whether such permit is requested for a single trip or for continuous operation.