How far can a load hang off the back of a truck in Washington?
Washington does not use the 4-foot marker threshold as its only maximum. Loads extending more than 4 feet beyond the rear require flags, while specified nighttime equipment applies at 4 feet or more beyond the bed or body. Separately, the permanent structure or load generally may not extend more than 15 feet beyond the center of the last axle.
The nighttime equipment rule measures from the rear of the bed or body. The 15-foot maximum is measured from the center of the last axle; the separate flag subsection uses the vehicle's rear and also covers side projection.
More than 4 ft beyond the vehicle rear, or more than 4 in beyond its sides: red or fluorescent-orange flags at least 18 in square must mark the load extremities. This flag provision is not limited to daylight.
At 4 ft or more beyond the bed or body: two rear red lamps, two rear reflectors indicating maximum width and one red lamp on each side indicating maximum overhang. Separately check flags at more than 4 ft beyond the vehicle rear or more than 4 in beyond its sides.
No part of the permanent structure or load may extend more than 15 ft beyond the center of the last axle, subject to the specialized-equipment exception stated in RCW 46.44.034.
The boundary wording matters
Washington says “more than four feet” beyond the vehicle rear for rear flags but “four feet or more” beyond the bed or body for the specified nighttime equipment. Exactly 4 ft reaches the nighttime threshold only when measured from the bed or body; exactly 4 ft from the vehicle rear does not trigger the rear-flag threshold. Side projection is a separate flag check.
A visibility marker does not by itself make a setup legal. Maximum projection, total length, securement and exceptions remain separate checks.
Add the axle-to-rear distance before comparing with 15 ft
Suppose the center of the last axle is 4 ft ahead of the verified vehicle-rear measurement point. Cargo extends 10 ft behind that point. The axle-to-load distance is 4 + 10 = 14 ft, within the 15 ft numerical maximum in RCW 46.44.034. The 10 ft rear projection still triggers flags. Measure from the bed/body separately for lighting.
These are hypothetical dimensions for understanding the origins, not a suggested transport arrangement. The structure or load, applicable exceptions, other dimensions and restraint still require checking.
| Projection behind vehicle rear | Distance behind last axle center | 15 ft comparison |
|---|---|---|
| 10 ft | 14 ft | Below the numerical maximum |
| 11 ft | 15 ft | At the numerical maximum |
| 11 ft 1 in | 15 ft 1 in | Above the general maximum |
Washington flags can also be required at night or for side projection
RCW 46.37.140(1) requires the specified flags when a load projects more than 4 ft beyond the vehicle rear or more than 4 in beyond its sides. That subsection is not restricted to daylight. A load extending only 3 ft behind the rear but 5 in beyond a side can still trigger flags.
At the specified lighting times, subsection (2) adds the lamp and reflector arrangement for a load extending 4 ft or more behind the bed/body. A nighttime bed/body measurement cannot by itself decide the separate vehicle-rear and side-flag conditions. Keep required flags as well as any required lights.
Check rear visibility, side visibility and lighting times
The projecting-load lighting provision calls for two rear red lamps and a red lamp on each side, each with at least 500 ft visibility in the specified direction. It also requires two red rear reflectors indicating maximum width and visible 100–600 ft under lawful lower-beam headlights.
RCW 46.37.020 includes the period from half an hour after sunset to half an hour before sunrise and specified poor-visibility conditions. Check that provision when a daylight trip includes fog or other reduced visibility. The specialized-equipment exception in RCW 46.44.034 has equipment and route conditions; it is not a blanket pickup exemption.
Checks the calculator cannot finish for you
- Measure from the center of the last axle for the 15-foot maximum.
- Confirm whether the specialized-equipment exception applies.
- Confirm total length, securement, vehicle limits, permit needs and route restrictions.
STATE PRESELECTED
Measure the actual setup, then review the rule result.
The calculator keeps unsupported cargo length separate from the legal projection named by the state rule.
Open with Washington selected →Washington overhang questions
Is the Washington 15 ft limit measured from the tailgate?
RCW 46.44.034 uses the center of the last axle. Measure from that origin to the end of the permanent structure or load, and review the provision's exception and other applicable limits.
Can I remove the flags once the lights are on?
Not when the separate flag provision applies. RCW 46.37.140(1) is not limited to daylight; check rear and side projection for flags in addition to the nighttime lighting rule.
Does less than 4 ft at the rear mean no flags are needed?
Not necessarily. The covered Washington flag provision also triggers for more than 4 in beyond the vehicle sides. The rear-only calculator does not measure that side projection.
OFFICIAL SOURCES
Rule information was last checked on Sep 8, 2026. Official pages and current law control if this summary differs.
Washington RCW 46.37.140 ↗Washington RCW 46.44.034 ↗Washington RCW 46.37.020 · lighting times ↗