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42 Truck Drayage Productivity Guide Within the terminal, the major determinants of turn time are as follows: The nature of the transaction, On-terminal chassis supply, Congestion in container stacks or parking areas, and Exceptions and trouble tickets. Causes of Long Turn Times Congestion at marine terminal gate queues and container yards is primarily caused by peaking, and can be exacerbated by limitations on working hours, external factors such as the OffPeak Pro- gram, or shortcomings of legacy facilities. Longer turn times can be expected for more complex transactions. Truckers prefer "double" moves (e.g., returning an empty container and pulling an import load on the same trip) rather than making two trips for the same work. On-terminal chassis supply is a focal point for process improvements and long-term institu- tional change, and is discussed in more detail later in the guidebook. Congestion in container stacks or parking areas is a function of terminal CY capacity, lift capa- bility, configuration, and peaking. Peaking is endemic in containerized shipping, and it would be impractical to build terminal capacity for the peak volumes. The bigger issue is the division of lift capabilities and staffing when vessels are in port. Exceptions and trouble tickets add an average of about an hour to affected moves. At about 5% of the total, trouble ticket transactions add about 3 minutes to overall average turn times. On a given day, turn times for trucks can vary substantially, even when trucks enter the ter- minal under similar conditions. There are a number of factors that can extend the time required. The average (mean) daily turn time may provide very little information about what is possible for any individual truck that day. When a terminal is operating close to its capacity, the prob- ability of high turn times significantly increases. In examining the patterns of delay throughout the day, the researchers found that turn times tended to come down later in the afternoon as the number of arrivals dropped. Furthermore, the probability of a truck experiencing an extra long turn time was lowest toward the end of the day. It should also be noted that the capacity of a terminal is dependent not only on the physical attributes of the terminal such as the num- ber of lanes and cranes, but also the amount of labor that has been assigned to work a particu- lar shift. Terminals attempt to anticipate high-volume periods and assign labor accordingly. If the terminal misjudged the volume for a particular day, higher average turn times and greater variability can result. The impact of congestion can be seen in the relationship between volume and turn times in Fig- ure 55. Although the general relationship is clear, the specifics will vary by terminal. In the exam- ples, the first terminal is relatively unaffected by volumes of up to 1,100 per day while the second shows marked increases in turn times for volumes above that level. Suboptimization A substantial portion of the delays and bottlenecks in port drayage are traceable to suboptimiza- tion of the complex intermodal system. Drayage firms and marine terminals would both prefer an even, predictable, and uninterrupted workload over the day, week, month, and year. The context in which they operate, however, makes that unlikely to ever happen. A system optimized for the drayage customers (the importers and exporters) is unlikely to be optimal for the marine terminal customers (the ocean carriers).

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Truck Turn Times 43 Drayage Volume vs. Average Turn Time - Jan - March 2009 90 80 70 Average Turn Time (min) 60 50 40 30 20 10 - 0 200 400 600 800 1000 1200 Number of Trucks Entering (a) Case 1. Import Deliveries vs. Non-Trouble Turn Time - 2008 100 90 80 Avg. Turn Time (min) 70 60 50 40 30 500 700 900 1100 1300 1500 1700 1900 2100 Daily Import Volume (b) Case 2. Figure 55. Congestion impacts. There is no one in charge of the entire process, so rational and well-informed actions by partic- ipants still do not optimize the whole. It is helpful to place drayage and terminal operations in context. Drayage of marine containers to and from port terminals is a complex process involving interactions between customers (importers, exporters, 3PLs), ocean carriers, terminal operators, and trucking firms. The funda- mental transaction is between the ocean carrier and the customer, with the customer paying for waterborne transportation of the goods inside the container. Marine terminal operations and drayage are intermediate steps, and both must cope with the movement preferences, policies, and capabilities of the ocean carriers and their customers. This intermediate position requires both drayage firms and marine terminals to cope continually with unevenness of demand, inconsistent priorities, mismatched information flows, and cost pressure.