Funded by the U.S. Department of Transportation over the last six years at a cost of $25 million, the TRANSIMS simulation package was developed by a Los Alamos Technology and Safety Assessment Division team led by Christopher Barrett. The software represents a major advance in transportation-flow forecasting procedures. TRANSIMS provides planners with a synthetic population's daily activity patterns (such as travel to work, to shop and to recreation, etc.), simulates the movements of individual vehicles on a regional transportation network and estimates the air pollution emissions generated by vehicle movements.
The travel information is derived from actual census and survey data for specific tracts in target cities, providing a more accurate sense of the movements and daily routines of real people as they negotiate a full day with various transportation options available to them. TRANSIMS is based on (and contributes to the further development of) advanced computer simulation codes developed by Los Alamos for military applications.
"TRANSIMS shows how key technologies developed for national security purposes can be applied to solve major problems faced by everyone who has to commute to work," said Los Alamos Director John Browne.
Originally designed to run on multiple workstations, TRANSIMS has since been adapted to perform over a parallel computing system such as the "Rockhopper cluster," a group of 128 networked Intel Pentium II personal computers at the Laboratory's Advanced Computing Laboratory. Realizing that city and state planners would have less sophisticated computer systems available to them than do national laboratory researchers, the simulation team has worked to maintain flexibility in the computer hardware combinations required to run the program. PricewaterhouseCoopers will further develop the user interface software and package the TRANSIMS software to create a version even more useable for state and local planning agencies.
The Los Alamos goal has been to develop a basic design and architecture for TRANSIMS by demonstrating its application for two transportation-planning organizations and to develop the long-term application of the TRANSIMS technologies in the transportation-planning market. The initial testing was done with the North Central Texas Council of Governments, the Regional Planning Agency for the Dallas-Fort Worth metropolitan area, and the Portland, Ore. Metropolitan Service District.
In the initial case studies, a 25-square-mile portion of the Dallas/Fort Worth region was used for demonstrating the first TRANSIMS version. Using the Laboratory's in-house version of the simulation, the team is currently focusing on simulating the metropolitan region of Portland, Ore., a model that requires 120,000 links and 1.5 million travelers—an order of magnitude larger than the Dallas/Fort Worth simulation of 10,000 links and 200,000 travelers. The Portland simulation also adds studies of mass transit.
"TRANSIMS will provide planners more accurate travel and air pollution emissions estimates and permit the evaluation of new approaches to reducing traffic congestion, air pollution and greenhouse gases that will contribute toward improving the quality of life for all Americans," said Department of Transportation Secretary Rodney Slater.
Spinoff applications of the simulation software have already been used by Los Alamos scientists to model the movement of travelers through airborne toxins such as might be released in a terrorist attack. Now the Laboratory is exploring EpiSim, an application of TRANSIMS that integrates disease models with patterns of interpersonal human contact. EpiSim will allow healthcare organizations to make more accurate predictions of the spread of epidemics in this era of high mobility.
Los Alamos National Laboratory, a multidisciplinary research institution engaged in strategic science on behalf of national security, is operated by Los Alamos National Security, LLC, a team composed of Bechtel National, the University of California, The Babcock & Wilcox Company, and the Washington Division of URS for the Department of Energy's National Nuclear Security Administration.
Los Alamos enhances national security by ensuring the safety and reliability of the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health, and global security concerns.