Bay Area PopulationSim Documentation
Welcome to the TM2 (Travel Model 2) Population Synthesizer documentation for the San Francisco Bay Area.
Quick Summary for Modelers
This population synthesizer creates realistic household and person records for transportation modeling in the 9-county Bay Area. It uses Census PUMS microdata and applies controls to match known demographic totals at the TAZ (Traffic Analysis Zone) level.
Key Features
- Geographic Resolution: County → TAZ → MAZ (Micro Analysis Zones)
- Population: ~2.5M households, ~7.5M persons across 4,735 TAZs
- Data Source: 2023 5-year American Community Survey PUMS
- Controls: Household size, workers, income, age, occupation, group quarters
Quick Navigation
What is PopulationSim?
PopulationSim is a synthetic population generator that creates realistic household and person records for transportation modeling. The TM2 pipeline synthesizes a population for the 9-county San Francisco Bay Area.
Overall Process Flow
PUMS Data → Geographic Crosswalk → Seed Population →
Marginal Controls → PopulationSim → Synthetic Population
Geographic Framework
- Region: 9-county San Francisco Bay Area
- Counties: SF, San Mateo, Santa Clara, Alameda, Contra Costa, Solano, Napa, Sonoma, Marin
- TAZs: 4,735 Traffic Analysis Zones
- MAZs: 39,587 Micro Analysis Zones
- PUMAs: 104 Public Use Microdata Areas
Exact Controls Used
Household Controls:
- Total households (including group quarters)
- Household size (1, 2, 3, 4, 5, 6+ persons)
- Workers per household (0, 1, 2, 3+ workers)
- Presence of children (yes/no)
- Group quarters (university, non-institutional)
Person Controls:
- Age groups (0-19, 20-34, 35-64, 65+)
- Occupation categories (management, professional, services, retail, manual/military)
Income Controls:
- 8 income bins from <$20k to $200k+
Detailed Reference Documentation
For advanced users and developers, comprehensive technical guides are available:
- TM2 Full Reference - Complete technical reference
- Detailed Output Guide - All output files and formats
- Detailed Synthesis Guide - IPF algorithm details
- Detailed Input Data Guide - Data sources and preparation
- Detailed Crosswalk Guide - Geographic relationships
- Detailed Control Generation Guide - Control marginals
Quick Links
- Source Repository: BayAreaMetro/populationsim
- Branch: tm2
- Questions? Open an issue on GitHub