Questions
Frequently asked
What this is, where the numbers come from, and what we will not say.
What is this?
A weekly reading of US port congestion, plus always-current data pages: vessel dwell at berth by port, container ships awaiting berth by complex, the monthly TEU volumes, and a rules-based import-friction read per complex. Built for importers, including e-commerce and FBA sellers, drayage fleets, third-party logistics operators, and freight forwarders' clients.
Where does the data come from?
Three public sources, no private data. The Bureau of Transportation Statistics open-data portal for AIS-derived container vessel dwell times. The BTS port and supply-chain freight indicators for ships awaiting berth (MARAD and the Marine Exchange), the truck planning-time index, and rail terminal dwell (the Surface Transportation Board). And the port authorities' own monthly container statistics for TEU. Every number traces to one of those.
What is the difference between all these dwell numbers?
This is the whole point of the site, so we keep them separate. Vessel dwell at berth is how long a ship sits at the berth, a ship metric. Container or box dwell is how long a container sits in the yard before it leaves, a box metric, and the one that drives your free-time exposure. Ships awaiting berth is a count of ships in the offshore queue, not a dwell time at all. We label every number with which of the three it is, and the methodology page defines each one.
What is the import-friction read?
A single descriptive label per port complex, built by a fixed rule from where its vessel dwell, ship queue and truck index sit against their own trailing-12-month normal. It tells you at a glance whether a complex is flowing, under some pressure, or congested. It is descriptive only, a summary of the current numbers, never a prediction. The exact rule is on the methodology page.
Why a trailing-12-month normal and not a five-year one?
The AIS-derived vessel-dwell and the ship-queue series are young, so a five-year seasonal band would rest on too little history to be honest. We compare each reading to the median and range of its own prior twelve months instead, which is the honest recent normal. The monthly TEU series run much longer, so for TEU we also show the year-over-year and the change against the 2019 pre-pandemic baseline.
How current is the data?
It varies by source and we label each reading with its own date. The vessel-dwell and ship-queue indicators update on a regular cadence. The monthly TEU numbers land weeks after the month they cover, so a TEU reading is always the latest month available, not the current week, and we say so. We date every reading to the period it reports, never to the day we pulled it.
Do you track ocean freight rates?
No. This site tracks congestion and volumes, not prices. We carry no ocean spot-rate feed and do not imply one. Rates are driven by capacity, demand and disruption; the numbers here are context for that picture, not a rate.
Is this routing, booking, or fee advice?
No. This reports where the congestion is from public data. It does not tell anyone which port to route through, when to book, when to pull a container, or how to handle a demurrage or detention charge. The last-free-day calculator counts days as mechanics only. The routing and the fee call are the reader's, made with their own bookings and contracts in front of them.