Forecasting Statewide Freight Toolkit (2008)

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32.1 Definition of Freight The term “freight,” in its most basic sense, refers to goods transported from an origin to a destination. Freight movement is not an end in itself, but serves an economic purpose: to ensure that products reach a location where they can be consumed. For this reason, demand for freight is considered a derived demand rather than a primary demand. In other words, the demand for freight stems from the economic requirement to move goods from a production site to a market. In transportation planning, goods transported incidental to the primary purpose of a trip, such as luggage accompanying an airline passenger on a business trip or tools accompanying a workman on a service call, are generally not considered freight. Other definitions of freight exclude certain types of goods movement due to the difficulty in identifying and fore- casting those freight shipments. For example, the Bureau of Transportation Statistics’ Commodity Flow Survey (CFS), an important source of freight data, excludes shipments from farms, government facilities, and most retail establishments (catalog and mail-order houses excepted). The CFS does not cover shipments of agricultural products from a farm to a pro- cessing center or terminal elevator (most likely short-distance, local movements), but does cover the shipments of these products from the initial processing center or terminal eleva- tor onward. These exceptions notwithstanding, goods moved over long distances and between cities constitute freight movements. Local shipments at the initial stage of a long-distance move- ment also are part of freight movements, and all other ship- ments including local delivery are called goods movements. Other definitions of freight focus on the modes that are used. Goods carried by rail, water, and air are generally con- sidered freight, while goods transported by truck may be con- sidered freight only if the truck in question carries goods that are also likely to be carried by other modes or is not limited to local delivery. Freight also can be labeled primary and secondary. Primary freight is defined in the Toolkit as goods moved over long distances and between cities, significant for statewide planning applications. Depending on the sources of data and the techniques that can be supported, this definition of pri- mary freight also includes goods moved by local truck that are at the initial stage of a long-distance movement, such as agricultural products traveling from farms to grain elevators. Secondary freight moves to and from distribution centers or through intermodal facilities. Forecasting techniques for secondary freight movements have been developed else- where and practitioners should seek other resources for this information, such as the Federal Highway Administration’s Quick Response Freight Manual.3 For the travel forecasting processes, the Quick Response Freight Manual classifies com- mercial vehicles into a) four-tire commercial vehicles, including delivery and service vehicles, b) single unit trucks with six or more tires, and c) combined trucks consisting of a power unit (truck or tractor) and one or more trailing units. 2.2 Statewide Freight Forecasting This Toolkit focuses on three types of long-distance, inter- city freight movements: 1. Shipments with an origin and destination in a single state; 2. Shipments with an origin and destination in two different states; and 3. Shipments with an origin and destination in two different states that pass through one or more intermediate states. In order to properly identify and forecast these three types of movements, the boundaries of the freight forecasting study area may extend well beyond a single metropolitan region or state. In many cases, a study area may include the entire con- tinental United States or even all of North America. C H A P T E R 2 Background and Definitions

While freight forecasting often is used to estimate future demand, it also may provide information on freight move- ments in the current transportation system. This could include evaluating changes in performance in response to changes in the current transportation system, such as increases in the price of travel on a specific facility, or devel- oping information on existing flows that could not be easily observed, such as freight flows by commodity using a specific roadway that could not be obtained by counting the number of trucks. 2.3 Freight Terminology In order to identify and forecast freight shipments, it is important to define key attributes of those shipments. The Transportation Research Board Committee on Freight Trans- portation Data refers to the desirable elements of a freight data- base using the mnemonic CODMRT, which stands for: • Commodity – The type of freight being moved. • Origin – The geographic start of the freight trip. • Destination – The geographic end of the freight trip. • Mode – The mode or modes being used to carry the freight. • Route – The route on the modal network used to carry the freight. • Time – The time period for which the freight data was col- lected.4 An implicit data element is also the flow unit, such as tons, dollar value, or vehicles, that is being recorded. The CODMRT mnemonic also is useful to describe the elements that will be produced by freight forecasts. The terms are defined as: • Commodity – A way of classifying the type of freight being shipped. Commodities are assumed to be indistinguishable based on the characteristics important in shipping. Com- modities of the same class are assumed to have the same 4 value per ton, the same density (weight per volume), and the same handling characteristics. There are several classi- fication schemes for freight, most notably the Standard Transportation Commodity Classification (STCC) codes of the American Association of Railroads, and the Standard Classification of Transported Goods (SCTG) a system developed jointly by U. S. and Canadian government agen- cies based on the Harmonized System to address statistical needs in regard to products transported. • Origins and Destinations – The geographic starting and ending points of a freight shipment. Origins and destina- tions generally do not refer to a specific street address, but to a larger identifiable geographic unit in which the address is located, such as a county, a state, or a census tract. • Mode – The vehicles and infrastructure used to transport goods. The most common modes defined in freight are truck, rail, water, air, and pipeline. Subcategories and com- binations of these basic modes may themselves be defined as modes. • Route – The sequence of specific individual facilities (such as, sections of roads, railroad tracks, etc.) that are used to transport freight between the origin and destination on a specific mode. • Time – The time of day, as defined by the Committee on Freight Transportation Data. For purposes of this Toolkit, it is assumed that time refers to the freight forecast time period as reflected in the flow data, such as tons per year or vehicles per day. • Flow Units – The way the freight flow is being reported and forecast as defined by all of the above attributes. If the freight flow is expressed for all modes, the flow unit must be expressed in a unit common to all modes, such as tons per year. Knowing all of the above characteristics for given ship- ments of freight makes it possible to sum those shipments to identify the total of all freight using a specific route or origi- nating from a specific location.