Second Generation Activity-Based Travel Demand Modeling System for Metropolitan Areas in Texas

Available Documents
Project Summary
Final Report

Primary Investigator
Jessica Guo
Civil and Environmental Engineering
1206 Engineering Hall
1415 Engineering Drive
Madison, WI 53706

Project Objective
To enhance, evaluate, and validate CEMDAP, which is an activity-travel demand microsimulator developed for metropolitan areas in Texas.

Project Abstract
The limitations of the traditional statistically oriented trip-based approach in evaluating demand management policies has led to the emergence of a more behaviorally oriented activity-based approach to demand analysis. The activity-based approach to travel demand analysis views travel as a demand derived from the need to pursue activities distributed in space. The conceptual appeal of this approach originates from the realization that the need and desire to participate in activities is more basic than the travel that some of these participations may entail. By placing primary emphasis on activity participation and focusing on sequences or patterns of activity behavior (activity schedule), typically with the whole day as the unit of analysis, a more realistic model of people’s adaptation to a changing travel environment can be achieved.

This is the sixth year of the TxDOT RMC2 project 0-4080, which involves developing an activity-based travel demand modeling software named CEMDAP – for a Comprehensive Econometric Micro-simulator of Daily Activity-Travel Patterns. CEMDAP takes as inputs the demographics and activity-travel environment of the study area for the forecast year. In addition the user will also be able to specify policy actions. The system will generate as outputs individual activity-travel patterns, which can then be processed by traffic micro-simulators to produce link flows and levels of service. This allows planners to evaluate policy impacts. Our research effort for the current year focuses on customizing CEMDAP for of the Dallas/Fort-Worth (DFW) metropolitan area using the new 4874-zone spatial representation. The system will undergo extensive testing and be compared against the trip-based NCTCOG modeling system currently used for travel forecasting for the DFW area.

Task Descriptions

  1. Evaluate the sensitivity of CEMDAP outputs to varying sample fractions (such as 10%, 25%, and 50%) of the overall population to determine if sampling can be employed from the standpoint of output accuracy.
  2. Examine the sensitivities of CEMDAP and the NCTCOG models to changes in socio-economic, land-use, and level-of-service factors. The travel patterns predicted by the two model systems will be compared for several hypothetical growth scenarios of year 2000.
  3. Produce a synthetic population of DFW for year 2025
  4. Compare and analyze validation statistics for CEMDAP and the NCTCOG model runs for years 2000 and 2025.
  5. Evaluate the computational efficiency of CEMDAP.
  6. Prepare a report documenting CEMDAP enhancements and validation and sensitivity testing results.
  7. Update CEMDAP user’s guide to reflect all changes and enhancements.

Project Information

  • Milestones, Dates: Duration: 8 months (January 1 to August 31, 2006)
  • Budget: $5,000
  • Student Involvement Two undergraduate students
  • Modal Orientation: Highway
  • Project ID: 07-07

Final Report