1. Dmitry Messen Houston-Galveston Area Council www.h-gac.com
Our Experiences with Land Use-Transportation Modeling Presentation at NYMTC Workshop May 1, 2008
Dmitry Messen
Houston-Galveston Area Council

2. Transportation-Land Use Connection
Why integrate?
You only need the integrated LUT model if you believe that people, businesses, and developers do (and will) respond to changing urban travel conditions
Good News: “Integration” affects the LU side only, TDM is already integrated with LUM
Regional travel patterns depend on the geographic distribution of people and jobs
What would it take to integrate LUM with TDM?
Pass relevant info (e.g., travel times and costs) from TDM to LUM and force the LUM to make use of it

3. Desired Model Features
Comprehensiveness
Bringing the major disciplinary “sub-models” of reality (population, economy, built environment) onto a single platform
Disaggregation
Tracking of individuals, households, jobs, businesses, building, housing units, parcels
Agent-based
Representation of decision-makers (households, businesses, developers) and decision-making process (location choice)
Simulation
Allowing uncertainty and randomness

4. TDM-LUM Iteration Forward-going iteration between LUM and TDM
Today’s land use decisions are informed by the transportation conditions of the present (or expectations of what they will be in the future)
Future transportation conditions are changed by today’s land use decisions
Dynamic Disequilibrium
Path-dependence: we have to live with the consequences of our choices (no “undo” button)
If a LUM forecast is using TDM inputs, then it’s TDM version-specific
If you add/remove a facility, you have to re-run the whole sequence

5. UrbanSim-TDM Integration

6. UrbanSim at H-GAC Since 2003 (DRAM-EMPAL before that)
Initiated by staff and supported by management
2 successful implementations (2025 and 2035 RTP)
Evolved together with the software
New model under development
From grid-based to parcel-based

7. How UrbanSim Works A micro simulation of a changing regional system
What changes?
Physical stock of housing and work space
Number of people and businesses
Where people and businesses reside
Who are the agents (decision-makers)?
Households, businesses, developers
Defined starting (base-year) conditions and decision-making rules
Agents are making location decisions
Where to reside
What and where to build
Annual increments; regional control totals

8. UrbanSim Land Use Forecasting Model
County Appraisal Data
Current Land Use
Past Land Use Change
Simulation
Statistical Modeling
Site attributes
Neighborhood attributes
Regional accessibilities
Future Road Network
“Builds” housing units and non-residential square footage
Known Future Development
Future Land Use

10. Types of Activities Data Development
Model-independent, never-stopping activity (requires comprehensive strategy)
Model Specification and Calibration
Research-type, relatively self-contained activity (most suitable for out-sourcing)
Scenario Development, Analysis, and Communication
Transparency and access (web-based mapping and data query applications)

11. Thematic Domains of Expertise
Built Environment
Parcels, buildings, infrastructure
Natural Environment
Slope, soils, vegetation, suitability
Regulatory Environment
Zoning, general plans, protected areas
People
Socioeconomic details (synthesis)
Economy
Macro (global, national, regional)
Micro (businesses, jobs)

12. Staffing Issues “Thematic” Specialization Skills Tiered Structure
Demography, economics, land use
Skills
GIS, data management, statistics, programming (especially for web-based apps)
Tiered Structure
Vision and strategy (leadership): goals design
Tactics (senior staff): process design
Execution (junior staff)

13. Experiences Data development is extremely important
Model’s credibility will depend on it
Process development is more important than the data itself (reproducibility, metadata, documentation)
There is no destiny, there are scenarios
Be prepared to explain that
Transparency is the best policy
Prepare to share data

14. Benefits De-politicized forecast
Relative unimportance of Control Totals
New answers beget new questions
Ability to model complex scenarios
Foundation for activity-based TDM

15. Challenges/Opportunities
If NYMTC can make it there, an MPO can make it anywhere!
Hardware and software limitations
Feedback between LUT model and control totals (regional, national, and global competition for jobs)
Keys to Success
Ambitious goals
Enthusiastic staff
Management’s commitment
Planning

16. Thank you!