§393.87 requires that any load projecting more than 4 feet beyond the rear of the vehicle be marked with red or fluorescent orange-red warning flags during daylight hours (each at least 18 inches square, located at the extreme rear of the load) and with red lamps visible from at least 500 feet during darkness or reduced visibility. Pole-trailers and similar configurations have analogous requirements at the projecting points.
Severity weight
Severity weight 1 in the Vehicle Maintenance BASIC. Notice-level — the more common upstream finding is unsecured projecting load, where §393.87 piles on top of §393.100 cargo securement.
How it gets cited
The most common pattern is flatbed and lowboy loads where the load shifts during transit and the rear projection grows past 4 feet without the driver re-flagging. The §393.87 cite arrives when a roadside inspector measures the projection and the flags do not match.
How to prevent it
- Carry red/orange-red flags and red battery-powered marker lamps in every flatbed truck.
- If the load projects close to 4 feet, flag it — the cost of a flag is zero; the cite is not.
- Re-check projection at every roadside stop; loads shift.
How Roadworthy HQ helps
§393.87 findings link to the vehicle's cargo-securement record and to the driver's training log, so a pattern across a fleet (rather than a one-off) becomes visible and corrective action targets the right driver or lane.