Metropolitan Transport Information System
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Port Truck Turn Time: Glossary

The nomenclature below was developed for the Los Angeles/Long Beach ports. To an extent it reflects specific practices at the port, e.g. congestion fees and corresponding behaviors.

“Time” refers to duration, not a clock reading.

1—Formal Nomenclature

These terms were proposed in the METRIS turn time study of 2011, and approved by the Long Beach-Los Angeles Truck Turntime Stakeholders Group.

Queue Time (Q)—Elapsed time between arrival in the queue and passage through the entry gate following all in-bound checkpoints. Ideally this measures the time spent waiting inadvertently, and actively advancing at the pace of the queue. GPS cannot discern driver intent such as arriving early for an appointment (which serves no productive purpose), or arriving early to secure a good spot in the queue (subtly different, this does serve a productive business purpose from the trucker's standpoint). Sometimes METRIS does detect behavior that doesn't involve active queuing, e.g. idling around a lunch van. Earlybird arrival at 4 am is easily flagged—very few trucks do this. Deliberate hangback at 4 pm is not readily detected—many trucks engage in this, and it may amount to an hour or more of queue time.

(In-)Terminal Time (T)—The elapsed time between crossing the entry gate (following all inbound checkpoints) and crossing the exit gate (after clearing all outbound checkpoints). May include transaction time (drop-off, wheeled or grounded pickup, flip-line, chassis service), trouble desk, roadability and other inspections, meal breaks. Terminals tend to subtract meal breaks when reporting turn time. This serves a terminal's internal purpose of documenting per-minute labor productivity, but it does not relate to the truckers' experience.

Transaction—Truck-terminal operation such as empty dropoff or import pickup, flip, visit to the trouble desk, or other service. One or more transactions occur on a visit.

Visit Time (V)—The sum of Queue time and In-Terminal time. Some other calculations of turn time do not include queue time.

2—Other Popular Nomenclature

Mission time—Same as visit time.

Total turn time—Same as visit time.

Trip purpose—Intended or completed transaction: import pickup, export dropoff, empty pickup/dropoff. When there is a difference between intended transaction and completed transaction, there is often a delay and possibly a re-entry or a trip to the trouble desk before the trucker finds that the intended transaction is not possible.

Turn Time—A generic and ambiguous term that variously refers to the time a truck takes (a) to make a trip to the port (which may involve one or more transactions at one or more terminals) and back to the home yard, or (b) to make a trip to the port, to a customer location and back to the home yard. METRIS defines a more specific set of durations with respect to a single terminal: Queue time, (In-)Terminal time and Visit time. We refer to “turn time” as a general area of port performance science.

Turnaround Time—Variant of “turn time”, but refers strictly to port turn time (transaction or visit time) not including delivery to customer as “turn” sometimes does. Note that “turnaround” below refers to an entirely different practice.

3—Additional METRIS Nomenclature

The following terms appear in METRIS reports.

Earlybird—A truck that arrives early for an appointment or gate opening. Trucks are known to arrive as early as 3 am for 7–8 am gates, and 3 pm for the 6 pm gate.

Exception—A visit that takes longer than the formal/informal standard. Flexibly defined, depending on the port and period.

FlyBy—A truck that advances to the entry gate without encountering a queue.

Hangback—A truck that arrives early to secure a good spot in the queue for a gate opening, but does not advance in the queue, so as to avoid the Traffic Mitigation Fee. At some terminals there are special lanes dedicated to hangbacks. They are a special case of Earlybirds; the distinguishing factor is motivation, and they can't always be detected.

Lingering—Trucks remaining inside a terminal to avoid the Traffic Mitigation Fee. From GPS we can determine that an exit was made soon after 6 pm, but we cannot sense motive, so the term refers to inferred intent rather than definitive discovery of the behavior.

Re-entry—Re-entering a terminal through an entry gate, after passing through the exit gate.

Slip-entry—Re-entering a terminal, not through an entry gate, after passing through the exit gate. Possible only at some terminals.

Slip-exit—Exiting a terminal, not through an exit gate. Possible only at some terminals.

Turnaround—Failed terminal visit (no transaction accomplished), characterized by a stop at the trouble desk only.

4—Miscellaneous Truck-Terminal Nomenclature

Chassis—Wheeled base frame on which a container is hauled by a truck.

Flip—To swap a chassis when loaded with a container. The box is lifted off one chassis and put on another, usually because the original chassis was found to be defective in a roadability inspection.

Roadability—Inspection to certify that a chassis is mechanically sound and suitable for use on public roads. Roadability checks performed by longshore labor were mandated in late 2011 in Los Angeles/Long Beach, following a court ruling.

Reefer—Refrigerated container.

Genset—Power generator for refrigerated container.

Trouble window/desk—Where truck drivers have to go when documentation is missing or incorrect, container is not cleared for pickup, etc.

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