El Paso TRANSIMS Case Study

The Transportation Analysis and Simulation System (TRANSIMS), which was developed as part of the Travel Model Improvement Program (TMIP), has been touted by its backers as a replacement for the four-step planning model. TRANSIMS is an integrated system of travel forecasting models which is designed to give transportation planners accurate, complete information on traffic impacts, congestion, and pollutant emissions. Because TRANSIMS represents a significant shift from the current state of practice, the transportation planning community will need to spend significant human and capital resources preparing for the transition. This report will provide some insight into these transitional issues based on research on the El Paso planning network in Texas. This report is comprised of three main sections. First the report provides a detailed overview of the TRANSIMS architecture. It is subsequently compared and contrasted with the four-step planning process. The next section describes the detailed data requirements, provides a description of the steps taken to create a TRANSIMS network for El Paso, and discusses the microsimulation results. Because TRANSIMS 1.1, which was used in this research, did not contain all the modules the research primarily focused on the microsimulation and emissions modules. Lastly, the TRANSIMS emission estimation process is described. Subsequently, this module is compared and contrasted to the MOBILE5 suite of emissions models. A "lessons learned" section is provided at the end of each section outlining the important findings.