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ULTRANS Modeling Team hits the "Home Stretch" on the largest travel model ever built for California

The 24 staff, scholars, faculty, students and consultants comprising the Urban Land Use and Transportation Center's (ULTRANS) California Statewide Travel Demand Modeling Team are three weeks away from being able to forecast how 12 million California households with 33 million members take 150 million trips every weekday across the State.

For fourteen months this team has assembled all the road, transit, bus, heavy rail and air systems in the State. They have studied the volumes of personal and commercial travel on every one of over 235,000 links. Car ownership was identified for all households and the demographic and employment characteristics of all households were derived from a variety of cross cutting data sets. The location of all employment in the State was specified in a zonal geography with over 5,100 travel analysis zones.

All of this comes together to assign persons and goods to travel modes, times and network elements in a dynamic system that considers the capacity of all systems and the effects of congestion in those systems on the choice of movements. Once the dynamic system reaches equilibrium with all trips assigned we will validate the model to known targets at over 200 crucial test points at the edges of regions around the State.

ULTRANS is on target to deliver this validated picture of a day in the life of California’s travel activity to Caltrans on September 30. This model of the status quo will be available to test alternative transportation investments and policies to determine how they would change the characteristics of travel in California. Tests of heavy rail and transit improvement, greenhouse gas policy options, toll charges and a near endless set of alternatives are being considered for testing. Caltrans has generously funded this effort but plans to share the model with all of California’s Metropolitan Planning Organizations to assist them in understanding the interaction of long distance trips and all other trips on the State highway system. The Rockefeller Foundation and the Surdna Foundation provided additional support for this model to ensure its timely delivery.

Back row: Chunyan Li, Ryan Boynton, Helen Peng, Nico Linesch, Alan Brownlee, Isaac Zafuta, and Kevin Stefan. Middle row: Shengyang Sun, Mike McCoy, Caroline Rodier, Brandon Haydu, and Doug Hunt. Front row: Debasis Basu, Bayarma Aleksandr, Giovanni Circella, Jackie Bjorkman, Dimantha De Silva, and Nate Roth.

Members not pictured: John Abraham, Abdel-Rahman Muhsen, Shengyi Gao, Eric Lehmer, Allie Scrivner, Laurel Torney and Caltrans Project Manager, Chad Baker.