§393.100 is the general cargo-securement rule: cargo must be firmly immobilized or secured on or within a vehicle by structures of adequate strength, dunnage or dunnage bags, shoring bars, tie-downs, or a combination thereof. The detailed working-load-limit math is in §393.102 and the commodity-specific requirements run through §393.116–§393.136.
The 50% / 80% / 60% rule (§393.102)
The total working load limit (WLL) of tie-downs must be at least 50% of the cargo weight. Working load limit per tie-down equals one-third of breaking strength (chain) or one-quarter (synthetic web).
The vehicle structure (headboard, walls, decking) must withstand:
- 0.8 g forward deceleration
- 0.5 g rearward acceleration
- 0.5 g lateral acceleration
These are the underlying numbers behind the "adequacy" finding the roadside inspector applies.
OOS criteria
Inadequate securement that creates an immediate hazard (cargo overhanging, tie-downs slipped, shifting visible) places the vehicle OOS until the load is re-secured to specification.
How to prevent it
- Train drivers on the §393 Subpart I working-load-limit math for the specific commodities they haul.
- Equip every tractor with a securement-aid kit (chains, binders, straps, edge protection) appropriate for the typical loads.
- Inspect tie-downs at the first stop after loading; loads settle in the first 50 miles and tie-downs slacken.
How Roadworthy HQ helps
A securement citation shows up in Roadworthy HQ as part of the inspection it came from, not as a record of its own: the app does not store individual violation codes. Log the roadside inspection on the vehicle's Inspections tab: date, state, level, driver, the number of violations, and whether it was out-of-service. For an out-of-service inspection the 15-day §396.9(d)(3) repair-certification countdown stays on that tab until you enter the certification date. The rule's 15 days cover every violation on the report, not only out-of-service ones, so for a non-OOS inspection that date is yours to track. The repair itself goes in the vehicle's maintenance log: date, type, what was done, who did it, and cost. DVIRs are logged per vehicle with the defect described in your own words, and a defect marked safety-affecting that is logged without a repair certification sends a critical alert.