Suggested Citation:
Mishra, Gouri Shankar, Page Kyle, Jacob Teter, Geoffrey M. Morrison, Son Kim, Sonia Yeh (2013) Transportation Module of Global Change Assessment Model (GCAM): Model Documentation. Institute of Transportation Studies, University of California, Davis, Research Report UCD-ITS-RR-13-05

The Institute of Transportation Studies at the University of California, Davis and Pacific Northwest National Laboratory (PNNL) embarked on a project to update and refine the transportation module of the Global Change Assessment Model (GCAM, formerly MiniCAM) – an integrated assessment model developed and maintained by PNNL.

The project encompasses the following four refinements to the transportation sector of GCAM:

1. Increased resolution to include the full spectrum of sub-modes and technologies available in passenger and freight transport
2. Refined estimates of input parameters so as to better represent real-world heterogeneity in a way consistent with the latest literature on transportation
3. Refined estimates of base year (2005) estimates of transportation demand, and disaggregation of IEA energy estimates between modes and size classes
4. Included the non-motorized modes of walking and biking

This project aims to better represent the heterogeneity and flexibility in the transport system to allow the modeling of a broader range of transport policy instruments including subsidies to public transit, government incentives for alternative technology, transportation fuel taxes, and public investments to increase the speed, service frequency/availability, and comfort of public and non- motorized modes.

This publication provides methodological detail on the new GCAM Transportation Module and contains the following:

1. Descriptions of the new transportation module in GCAM
2. Details about the data sources and methodology adopted to estimate the exogeneous input 
parameters
3. A summary of the region-specific transportation data for base year (2005)
4. Comparisons of these estimates across regions and modes
5. Highlights of the uncertainty and shortcomings in our estimates