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117 Exhibit 4-1. Conceptual framework. CONCEPTUAL MODEL Emissions Health Effects Energy Output Concentrations Economic Activity GDP Commodity Fuel GHGs Freight Activity flows consumption CAPs Ton-miles Hp-hr HAPs TEUs improves the accuracy of freight transportation emissions. fulfill such needs. In this case, this entails a closer look at the The emission outputs are associated with either a product (or information needs of the four main categories of stakehold- quantity of a given commodity), vehicle activity (e.g., VMT), ers (private industry, transportation agencies, environmen- freight activity (e.g., measured in ton-miles), link, node, or a tal regulatory agencies, and environmental organizations), geographic area. The Conceptual Model includes processes for which are addressed in Section 4.3.1. Based on these needs, the spatial and temporal allocation of emissions in order to five types of applications are created as discussed in Sec- support dispersion models and health risk assessments. Lastly, tion 4.3.2 (global/national, freight corridor, metropolitan, it includes processes for the evaluation of emissions, including facility, and supply chain). To fulfill the objectives of these scenario analysis and uncertainty analysis. five types of applications, six functional areas are discussed The broad nature of the assignment warrants the use of in Section 4.3.3 (transportation network design, planning of an established methodology to ensure that the Conceptual transportation services, execution of transportation opera- Model will lead to the development of an actual model in tions, calculation of freight emissions, allocation of freight the future. Information engineering allows a hierarchical emissions, and evaluation of freight emissions). and structured analysis of a business area (i.e., freight trans- Analysis is the phase that examines the business processes portation emissions), and uses simple but comprehensive needed to run a functional area, how these processes inter- modeling/diagrammatic techniques. There are four main relate, and which input parameters are needed. Section 4.3.4 phases in information engineering, typically depicted in a describes the business processes included in the Conceptual pyramid (Exhibit 4-2). Model, and Section 4.3.5 provides a simplified process flow describing how information flows between processes. Strategy planning is the phase that addresses how technol- System Design is the phase that determines how selected ogy can be used to achieve specific goals such as creating processes in the selected business area are implemented in new opportunities, creating a competitive advantage, or procedures and how these procedures work. This phase is advancing environmental stewardship. Strategy planning outside the scope of this project. creates a high-level overview of the information needs of System Construction is the phase when the system is con- the stakeholders and the system functional areas that will structed with the assistance of programming tools and code generators, and coupled with system design tools. This phase is not included in the scope of this project. Exhibit 4-2. Four phases of information engineering. 4.2 Freight Modeling Plan Conceptual Strategy The design of the Conceptual Model must take into consid- Model eration current developments in freight modeling. As presented Analysis in NCHRP Synthesis 364: Forecasting Metropolitan Commercial and Freight Travel, (185) good freight models should incorpo- Systems Design rate the following attributes: Future Developments Ability to depict local characteristics: the model should Systems Construction consider the appropriate spatial resolution to capture the unique characteristics of the specific region for which it is

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118 developed, including the appropriate characterization of 4.2.2 State/Intercity Corridor Models freight facilities and transportation links with their partic- Statewide models, typically developed by state DOTs, rep- ular restrictions to freight vehicles. Link with national and regional databases and models: resent a variation of the four-step process used by MPOs to model transportation activity at the metropolitan level freight flows into, out of, or through the region of interest described in the following subsection. The main difference to should be related to the "outside world." The model should MPO models is that their focus is on (multimodal) commod- distinguish between external trips serving the region, inter- ity flows rather than truck flows. The primary source of this nal trips, and through trips. information is the TRANSEARCH database and FAF, as well Link to economic forecasts and trends: independently of as other roadside data sources. Flows are assigned geograph- the geographic scale of an application, consideration should ically through the application of an economic input-output be given to the interaction between freight flows, commod- model that links commodity flows to land use and employ- ity flows, and economic forecasts. ment activity in traffic analysis zones (TAZs). Most models Ability to consider technological changes: a freight model then allocate the assigned commodity flows to modes by using should be flexible enough to incorporate the effects of new estimates of vehicle payload. Methods for mode split, as well technologies on logistics patterns. as treatment of non-truck modes, range widely in terms of levels of sophistication. Freight modeling applications are typically divided by geo- graphic scale and application purpose. First, national-level applications are based on high-level national and international 4.2.3 Metropolitan/Urban Models economic flows and trade activity, providing a framework for Very few MPOs attempt to do freight modeling, and most different geographic regions to assess overall freight activity travel demand models are limited to truck movements derived generated by economic trends. Second, state-level or corridor from the four-step process. In the first step, trip generation, applications are generally based on commodity flows, which the models estimate trip production and consumption based are linked to economic activity and translated to freight on economic activity (i.e., land uses) by truck type and TAZ. flows by allocation to specific transportation modes. Third, The models also estimate external trips. In the second step, trip metropolitan/urban applications tend to focus on truck distribution, the model combines internal and external truck movements modeled through traditional travel demand trips by truck type onto an origin-destination matrix. The models, which are based on the four-step process. Finally, third step, mode split, is not performed since only trucks are shipper/carrier applications focus on modeling goods distri- considered. Finally, in the fourth step, network assignment, bution through tour-trip optimization to maximize delivery the model assigns truck trips by truck type to highway links, efficiency and minimize logistics costs. usually at specific time-of-day periods. The Conceptual Model incorporates these four levels of MPO models have three main pitfalls when applied to application into a common framework, but it recognizes the freight. First, there are concerns regarding whether truck inherit differences in objectives and analytical procedures to activity can be modeled effectively without a direct link to the model freight activity. The Conceptual Model also considers economic activity that is creating the demand for a particular a fifth application that models activity at a specific freight commodity. Second, the standard trip generation/attraction facility (e.g., port terminal, railyard, airport), which is an methods are based on unique trip tours (one origin and one important application for the analysis of local emissions and destination), but many truck shipments are based on multi- air quality. stop pick-ups/deliveries. Third, even though trucks account for the majority of urban freight movements, consideration should also be given to other modes of transportation. This is 4.2.1 National/International Models important in emission studies, given that the local air quality The Freight Analysis Framework (FAF), developed by impacts of freight facilities can be substantial. FHWA, is a commodity origin-destination database that esti- mates tonnage and value of goods carried by mode of trans- 4.2.4 Shipper/Carrier Models portation within 114 domestic and 7 international regions. Different methods are used to disaggregate interregional flows Shippers, carriers, and logistics operators are responsible for into flows among individual counties over specific transporta- the logistics of goods movements, and use processes and mod- tion facilities. These methods are based on geographic dis- els to manage these operations. These models, usually in the tributions of economic activity rather than on accurate realm of the private industry, range from strategy-level models depictions of local conditions. that handle supply chain design (e.g., facility location) to tacti-

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119 cal models that design routes and multistop deliveries to oper- of simplistic methodologies to calculate fuel consumption that ational models that handle day-to-day operations such as car- do not consider factors that might be relevant in the evalua- rier selection. Commercial vehicles engaged in distribution tion of freight transportation emissions. For example, emis- operations typically travel in multistop tours, rather than a one sions occurring at nodes are not always considered, nor are originone destination trip. As a result, such movements are idling emissions. Calculated fuel consumption in these mod- not well modeled by MPO models. els is generally not sensitive to changes in equipment payload, Previous research suggests the following three core ideas nor are other parameters such as terrain grade or congestion about how logistics organizations should be handled in a considered. Additionally, only CO2 emissions can be esti- good freight model: mated since the software tools calculate emissions from fuel consumption. Logistics organizations focus on total logistics costs (trans- portation and inventory) when making decisions on how to 4.2.5 Other Models, Methods, ship materials across the supply chain. As a result, models and Data Sources should also account for how changes in transportation pat- terns could affect inventory costs. This section discusses alternative or developing models, Logistics costs are heavily influenced by how supply chains methods, and data sources used to measure emissions from are designed, especially by how facilities are located in com- freight transportation. In contrast to the models described parison with the locations of suppliers and final consumers. previously, these new or developing models represent freight Therefore, a freight model should take supply chain design emissions in novel ways. Because these models, methods, into consideration. and data sources are currently in development, they are not As shipment sizes decrease in exchange for increased fre- explored in depth, but are briefly summarized. quency (to minimize inventory costs), carriers increasingly combine shipments in vehicles using cross-dock operations, GIFT use special routing software to optimize routes with multi- ple stops, and reduce empty equipment repositioning costs. The Geospatial Intermodal Freight Transportation (GIFT) model, developed by researchers at the Rochester Institute of EPA's SmartWay Transport Partnership has developed a Technology, assists users in understanding the environmen- number of tools that are directly relevant to the private indus- tal impacts of shipping routes and choosing routes that try, including the Carrier FLEET Model, the Shipper/Logistics minimize fuel use and emissions. Compared to models dis- FLEET Model, and the DrayFLEET Model. The Carrier FLEET cussed previously that focus on modal activity, the GIFT Model allows firms to estimate the environmental perfor- model offers a more complete supply-chain analysis of freight mance of their fleet using different technologies and opera- movement. (190) tional strategies. The Shipper/Logistics FLEET Model allows Instead of using modal activity and emission factors, GIFT shippers to score their operations on the use of different oper- models a supply chain as a collection of links and nodes, in ational strategies, including the use of SmartWay carriers. which each link represents a trip by specific mode, and each The DrayFLEET model is focused on ports, providing the node represents freight handling locations, including railyards, ability to measure the air emissions impacts of employing intermodal centers, and warehouses. Each link and node such strategies as container chassis pools, off-peak gate hours, incorporates properties of the selected mode, such as truck etc. EPA also has developed the Diesel Emissions Quantifier emissions and fuel economy, as well as properties of the trip, to assist firms in estimating the benefits of retrofits. These including grade, distance, and congestion. In addition, each tools tend to be limited in scope, focusing on single modes link and node includes freight cost information. individually or on the assessment of individual emission By analyzing this structure, model users can make an reduction strategies. informed choice about freight shipment routes, depending There is also a rapidly growing number of private software on their shipping needs. For example, a shipper could use products intended to help businesses measure their carbon GIFT to select the most economical route, the "greenest" footprint, including from transportation operations and route, or a route that includes specific modes or waypoints. supply chains. Examples include Microsoft Dynamics AX's Alternatively, a shipper could apply weighted preferences to Environmental Sustainability Dashboard, (186) CSRWare's each characteristic to optimize the shipping route consider- Enterprise Sustainability Management Platform, (187) Revo- ing all parameters. lution ID's Foundation Footprint, (188) and Enverity's ghg- GIFT is currently in development with support from fed- Track. (189) The main issue with these current tools is the use eral and state governments, as well as private industry.