Title

The California Statewide Travel Demand Model (CSTDM): A practical tool for transportation analysis

Time

1:30 p.m. – 3:00 p.m

Location

1065 Kemper Hall, UC Davis

Abstract

The California Statewide Travel Demand Model (CSTDM) simulates the
individual person and vehicle movements made by all California residents and employees using the available
networks of roads and transit services over a 24-hour weekday. It includes five sub-models of
transportation demand:

• short-distance personal travel, including all tours where all stops are less than 100 miles from home, accounting for about 92% of all trips and 78% of all VMT in a typical weekday, using an activity-based approach;
• long-distance personal travel, including all trips to destinations more than 100 miles from home, accounting for about 1% of all trips and 8% of all VMT in a typical weekday, using nested logit models of combined trip, destination and mode choice for different purposes;
• short-distance commercial vehicle movements, including all work-based vehicle tours where all stops are less than 50 miles from work, accounting for about 6% of all trips and 8% of all VMT in a typical weekday, using a tour-based simulation of each vehicle and the stops it makes;
• long-distance commercial vehicle movements, including all road-based freight movements longer than 50 miles, accounting for about 0.5% of all trips and 1% of all VMT in a typical weekday, using a spatially disaggregated input-output matrix of commodity flows; and
• external vehicle trips, with one or both ends external to California, using singly-constrained gravity models

The networks of available services and resulting time and costs are represented for 11 modes,
including: walk, cycle, auto SOV, auto HOV-2, auto HOV-3+, local bus, rail, and air for personal
travel along with light, medium (single-unit) and heavy (multi-unit) vehicles for commercial movements.
Paths including combinations of these modes, such as SOV-to-rail-to-local bus, are also considered.
Local bus is represented using synthesized in-vehicle and out-of-vehicle times that are functions of
auto-HOV3+ times, densities at the origin and destination and specific system service levels.
This avoids the very-resource intensive need to code each local service explicitly.

The various model components have been estimated and calibrated using a dataset of observations
of transportation behavior developed by combining the results of household travel surveys done
across the state and in the major MPOs over the period from 2000 to 2005. The full system has
been validated against traffic screenline counts for the year 2008, including some 125 million
trips and 800 million VMT. It can be run on a single 8-core PC, requiring just over 24 hours to
complete an iteration where the demand is generated and loaded onto the networks until convergence.

The CSTDM has been developed as a practical tool for policy analysis and forecasting by ULTRANS at
UC Davis together with HBA Specto Incorporated for Caltrans.

Biographical Sketch

Dr John Douglas Hunt is a professor of transportation
engineering and planning in the Department of Civil Engineering at the University of Calgary in Canada.
He is also a Senior Fellow in the Institute for Sustainable Energy Economy and Environment.
He has 30 years of experience in transportation and urban system modelling in both research and
practical application environments. Dr Hunt studied Urban Systems and Architecture at Cambridge
University for his PhD and has worked in Europe, the United States, and Canada. Specific places
he has helped to model include London, Edinburgh, Dortmund, Naples, Dublin, Detroit, San Diego,
Phoenix, Baltimore, California, Los Angeles, San Francisco, Sacramento, Ohio, Washington State,
Sweden, South-east England, Chile and Columbia – to name just some. He has well over 100 papers
and presentations and teaches courses in probability and statistics; transport demand modelling;
transport economics; and land use transport interaction analysis.

Dr John Douglas Hunt is a professor of transportation  engineering and planning in the Department of Civil Engineering at the University of Calgary in Canada. He is also a Senior Fellow in the Institute for Sustainable Energy Economy and Environment. He has 30 years of experience in transportation and urban system modelling in both research and  practical application environments. Dr Hunt studied Urban Systems and Architecture at Cambridge  University for his PhD and has worked in Europe, the United States, and Canada. Specific places  he has helped to model include London, Edinburgh, Dortmund, Naples, Dublin, Detroit, San Diego,  Phoenix, Baltimore, California, Los Angeles, San Francisco, Sacramento, Ohio, Washington State,  Sweden, South-east England, Chile and Columbia – to name just some. He has well over 100 papers  and presentations and teaches courses in probability and statistics; transport demand modelling;  transport economics; and land use transport interaction analysis.