Component Design Report: International Transportation Energy Demand Determinants Model
July 12, 2017
Executive Summary
This Component Design Report discusses working design elements for a new model to replace the International Transportation Model (ITran) in the World Energy Projection System Plus (WEPS+) that is maintained by the U.S. Energy Information Administration. The key objective of the new International Transportation Energy Demand Determinants (ITEDD) model is to enable more rigorous, quantitative research related to energy consumption in the international transportation sectors.
A number of similarities will exist between the ITEDD and ITran models—for example, both models will provide measures of energy consumption by fuel type. However, ITEDD’s design will differ from that of ITran in several key respects:
- Initial specification: A novel representational scheme will estimate travel demand, modal splits, and realized demand within ITEDD in a staged process that will be mediated by demand determinants such as vehicle stock availability. While many initial determinants will be estimated using current techniques, the new model will account for several new factors based on EIA’s experience in modeling other sectors, such as accounting for unmet demand in the electric power sector.
- Demand determinants: The ITEDD model will consider a wider array of demand determinants than traditionally considered, such as population, income, industrial output, energy product trade, relative fuel prices, land use, infrastructure limitations, and policy measures. Careful consideration will need to be given to how the model interacts with other parts of the WEPS+ environment, including macroeconomic conditions across regions. Setting parameters for the model will also require more extensive and continual research than in the past.
- Calibration and integration: The ITEDD model will incorporate an iterative calibration procedure to refine the technical coefficients that account for developing trends in the demand for transportation fuels and related product volumes and prices. Energy demand and these and other related factors will be endogenously determined within the ITEDD model and the overall WEPS+ environment to the greatest extent possible. The new model will also effectively operate across a wide range of fuel supply and macroeconomic scenarios.
- Regional breakout: The ITEDD model will include a flexible regional design that allows us to consider important regional distinctions that may be identified in available data but are not considered in ITran. For example, travel behavior and fuel consumption in Chinese rural areas have a very different consumption profile than in urban areas. As a result, transportation demand in China is best modeled as two separate regions to properly account for the two distinctly different sets of consumption patterns.
- Policy study capabilities: The prototype version of the ITEDD model will be tested for the capability to incorporate and analyze a wide variety of policy and regulatory cases in a straightforward and transparent manner before the final model is implemented.
- Modeling platform: The prototype version of the ITEDD model will use the Python and Fortran modeling platform currently supporting WEPS+, although the decision for the modeling platform of the final ITEDD model is undetermined at this time.
Because the main goal of the project is to produce a model that is more robust, transparent, and accessible to modelers than ITran, a major challenge in the ITEDD model’s development is adhering to this goal without sacrificing the detailed representation needed to accurately project international transportation fuel market dynamics.
Several of the elements included in the prototype version of the ITEDD model will rely on approaches currently used in the WEPS+ environment. These elements include the use of macroeconomic and historical fuel consumption data provided by other models in WEPS+. This approach is particularly true for fuels that are heavily linked to international trade, such as those used in marine transport. Future improvements made to other parts of WEPS+, such as a more robust representation of the international oil supply conditions, will be addressed during the finalization of the ITEDD model.