Activity-Based Models and ACS Data D. Niemeier University of Califonia, Davis

Introduction Overview of primary data products Overview of activity-based models Key data needs for emerging models Advantages and disadvantages of ACS

Primary Data Products Census Microdata Sources  Decennial Census PUMS  ACS PUMS Census STF3A (SF3, 2000) CTPP NHTS ACS Tables

Current  Practice ModelModel DescriptionPractical Application ALBATROSS A rule-based approach using decision tree formalism to model heuristic choice. Case study for the Rotterdam region in Netherlands AMOS Specific search rules are used for finding feasible schedule adjustment. AMOS survey and TDM policy analysis applied to Wash DC Day Activity Schedule Model Nested logit model used for estimating individual’s multidimensional choice of daily activity patterns. Portland Day Activity Schedule Model System MORPCTour-based using choice models.Mid-Ohio Region TDM PCATS Maximizing utilities with considering different types of constraints. Osaka and Kyoto, Japan Portland Model Based on Bowman and Ben-Akiva’s Day Activity Schedule Model. Portland Metropolitan TDM STARCHILD Predict alternative activity patterns using multinomial logit models. Case studies from Orange County and Portland

Activity-Based Models In general, key step in which census or “other than travel survey” data plays a role:  Generation of synthetic households/population TAZ using socio-economic variables (PUMS) Other steps similar for both 4-step and activity-based (e.g., calibration/validation)

Population Synthesis MORPC Pop. Synthesis Model

Advan/Disadv for Emerging Models Subject ACS Advan ACS Disadvan Explanation Self ResponsexPercentage of individuals who responded Household ResponsexPercentage of households who responded Questionnaires Completedx Ratio of completed questionnaires to all of the questionnaires Timeliness of Data Availability x Publication of data after collection; 1-year, 3- year, 5-year averages will be available every year Continuousx Data will be continuous; 1-year, 3-year, 5-year averages will be available every year Data Availability for Research, Policy Makers, etc. xMonthly data will be available Geographic Area Definitionsx Down to block groups where are Census is down to census tracks

Practical Issues/Research Needed Geographic resolution How to map between or fuse data sources Need for demog. data at HH and person-level ACS defining HH characteristics may not match census information Finally, more research and information on control variables, use and affect within ACS