RouteAllWashington Oversize Load Signs, Flags And Lights
Sources Reviewed: October 23, 2026
Washington’s special-permit equipment rule specifies load signs and corner flags, with different treatment after dark. Named overlength exemptions appear in another rule, so do not apply the sign instruction without checking the vehicle category.
On This Page
What Does Washington Require On Load Signs?
WAC 468-38-155(8) specifies front and rear OVERSIZE LOAD signs, at least 7 feet wide by 18 inches high. Black lettering is at least 10 inches high with a 1.4–1.5-inch stroke on yellow. Keep lights and plates unobstructed. Display the signs only during transit of an overdimensional load, removing or retracting them otherwise. Inspect the rear panel after loading; boosters and other equipment can interfere with its view.
Where Do Washington Flags And Lights Go?
The rule places flags on all four corners of overwidth loads and extreme ends of protrusions, projections or overhangs as required by RCW 46.37.140. During darkness, lamps required by that statute occupy each required flag position. This is not a statement that a daytime cloth flag illuminates a rear projection. Check the statutory lamp placement and the permit’s actual travel authorization before planning a late arrival.
What About An Overlength-Only Combination?
WAC 468-38-075 exempts specified qualifying overlength vehicles or loads from several special-permit restrictions, including load signs. This is a defined list, not an exemption for every long trailer. Match the exact configuration with the listed category before relying on it. If width or another dimension is also excessive, ask the permit office how that affects the movement rather than extending an overlength exception yourself.
How Should A Multi-State Crew Prepare?
Compare the Washington sign measurements with the incoming equipment and separately brief the pilot cars on their own standards. Photographing the loaded rear view while parked can help dispatch identify an obscured sign or lamp before release. It does not replace the physical equipment inspection. If an attachment changes, walk around again and review the full road sequence before confirming the navigation plan.
How Can RouteAll Help Prepare The Washington Trip?
Import the issued permit into RouteAll and review its extracted road sequence while parked. Compare the first road, connecting junctions and final approach with the document, then share the reviewed route with the crew. Keep your equipment checklist beside that route review. RouteAll helps organize and navigate the permitted route; it does not inspect banners, certify flag placement or establish that a lighting setup complies with the permit.
Before You Roll
Match the measured load to the permit category. Inspect the actual front, rear and projecting points after securement. Resolve any unclear marking instruction with the issuing authority before dispatch, and revisit it when equipment or the load changes.
Further Reading
- Compare State Sign Requirements
- Prepare The Oversize Equipment Checklist
- Read The Washington Oversize Permit
Sources And Scope
Original driver reference based on the identified official publications, reviewed October 23, 2026. The issued permit, current law and applicable commercial-vehicle rules control. Load markings and escort equipment are distinct. This page identifies the source scope and does not replace a complete equipment inspection.
- Washington WAC 468-38-155 — Current special-permit flags, load signs and nighttime lamp reference.
- Washington WAC 468-38-075 — Named qualifying overlength exemptions; not blanket permission.