OAR 734-075-0030: Open Sides Covering

(1) Units transported with uncovered open sides must have adequate cargo securement to prevent shifting or loss of any accessory parts included with the load. (2) The open side of units transported more than 25 miles must be covered with a rigid material such as plywood, hardboard or similar material: (a) In lieu of rigid material, plastic covering can be used, provided a grillwork of lumber or other material is used to prevent billowing of the plastic material; or (b) The grillwork is not required if the open side is covered with plastic made of non-tearable, cross-laminated polyethylene material, provided the material adequately prevents billowing.