1. UrbanSim
Integrated Land Use, Transportation, and Environmental Simulation Alan Borning Dept of Computer Science & Engineering and Center for Urban Simulation & Policy Analysis University of Washington Joint work with Paul Waddell & other faculty, staff & students

2. Using Models in Urban Planning
Integrated land use and transportation models can provide an important tool for exploring policy alternatives and possible urban futures
What if …?
We built a new light rail line, and added significant connecting bus service?
We established an urban growth boundary and zoned for increased density and mixed-use, with the goal of promoting transit-oriented development?
We built a network of new freeways and widened feeder arterials?
Analogy: SimCity, but with requirements for realism
Unfortunately, models in standard use are inadequate

3. UrbanSim
Highly interdisciplinary project at the University of Washington
Participation from faculty and students from many schools and departments
Paul Waddell, project director (Evans School of Public Affairs)
Alan Borning, co-director (Department of Computer Science & Engineering)
Major funding from the Digital Government program, National Science Foundation
Additional funding from Puget Sound Regional Council, Environmental Protection Agency, plus other federal, state, and regional agencies

4. UrbanSim (2)
The system is fully operational and documented, and is distributed under an open source license (GPL) via our website
Used experimentally in Honolulu, Hawaii; Eugene, Oregon; Salt Lake City, Utah; Houston, Texas, Paris, France; Tel Aviv, Israel
First major application to a public planning project starting this summer in Puget Sound region (Seattle and surrounding metropolitan area)

5. Outline UrbanSim inputs and outputs UrbanSim system design
(Very brief!) Our software engineering methodology
Current work on enabling citizen access to UrbanSim’s results and simulation capabilities
(If time allows) Value Sensitive Design theory and methodology

6. UrbanSim Input Data – Integration Process

7. 150 Meter Grid Cells
150 square meter grid cells Green Lake neighborhood, Seattle

8. UrbanSim – System Design
Modeling:
Provide interacting component models that represent different agents and processes in the urban environment
Component models loosely coupled (for software engineering reasons); communicate via a shared database
Dynamically simulate annual time steps
Example component models:
Residential Location
Employment Location
Land Price
Real Estate Development
Demographic transition
Travel (external model)

9. Example Model - Residential Location
Households that need to be placed in new locations in a given simulated year:
Existing household predicted to move by Household Relocation Mode
New households from Demographic Transition Model
Available housing to move into:
Units vacated by households that moved out
New housing from the Real Estate Developer Model
Residential Location Choice Model places these households in available housing

10. Residential Location Model (2)
A probabilistic model
Outcome: which grid cell the household moves to
Influences on choice include:
Household characteristics (income, age of head, number of children, race, etc)
Characteristics of available housing (cost, type, neighborhood land use mix and density, access to neighborhood employment, travel time to central business district, etc)
Calibrated to local data for the region being simulated
Database takes care of accounting for where household is located, which units are occupied, etc

11. Software Engineering - Extensive Testing

12. Indicators
Indicators provide the principal mechanism for summarizing results from the simulations for different stakeholders
Indicators can be computed for various geographies (the region as a whole, cities, neighborhoods, grid cells, etc)
Examples:
Population density
Average household income
Acres of vacant developable land

13. Example simulation output: Map-based indicator display for Puget Sound region

14. Results from Salt Lake City: comparing predicted land prices in 2030 for the adopted Long Range Plan with a no-build alternative

15. Aside regarding indicators and the workshop theme
National Infrastructure for Community Statistics: a proposed web-based utility that facilitates access to detailed, current community-level statistics
What if we also facilitated access to selected community-level statistics for the next 30 simulated years for various possible scenarios of the future?

16. More Direct Support for Public Access and Deliberation
Three interrelated projects:
Indicator Browser
A web-based system for browsing through scenarios and indicators
Indicator Perspectives
Organizations with widely differing views on land use, transportation, and the environment analyze and comment on indicators and scenarios
U-Build-It
Planned system to give direct access to the simulation to citizens and elected officials

17. Indicator Browser
Web-based chooser for selecting scenarios and indicators to example
Dynamic generation of output
Ready-to-hand documentation
Documentation is linked directly from chooser
Live documentation – includes:
Actual SQL code to compute indicator
Test cases for SQL code

18. Indicator Browser – Live Documentation

19. Balancing Freedom from Bias with Value Advocacy
Wanted to describe why a given indicator was important to different stakeholders
We found this very difficult to do within relatively neutral technical documentation
Approach: also provide Indicator perspectives
Allow organizations or groups to present their own perspective on which indicators are important and why, and how to interpret them
In early stages - two prototype perspectives developed so far

20. Indicator Perspectives – Initial Partners
Northwest Environment Watch
an environmental group
Washington Association of Realtors
a business association
King County Budget Office, Benchmark Program
a government agency

21. Indicator Perspectives - Example

22. U-Build-It
Would like members of advocacy groups, business associations, and motivated citizens to be able to construct their own scenarios to be simulated
But UrbanSim is quite complex
Approach: a web-based system that will provide a rich set of component parts that can be mixed and matched to assemble a scenario to be simulated
User chooses among various alternatives (3 alternatives for a light rail system, 4 zoning alternatives, etc)
System assembles these into a scenario and (if not simulated already) puts this in a queue to be run
Results to be available via the Indicator Browser

23. Value Sensitive Design
An approach to the design of technology that accounts for human values in a principled and comprehensive manner throughout the design process
Central to our work on more direct support for public access and deliberation
Primary developer of VSD: Batya Friedman, Information School, University of Washington

24. Value Sensitive Design Contributions
Principled basis for considering value issues in the design of a technological system
Actively design the technology to support particular values (rather than engaging in a retrospective critique)
Methodology explicitly designed to consider:
Potentially diverse user population
Both direct and indirect stakeholders

25. Applying VSD to UrbanSim – One Example
How do we deal with the multitude of strongly held and often conflicting values held by different stakeholders? We distinguish:
Explicitly supported values
Stakeholder values
Explicitly supported values are not the same as the personal values of the designers – they are subject to a principled analysis of arguments for their inclusion

26. Explicitly Supported Values
These are taken as given, and are explicitly supported by the system as well as possible
Principal values:
Support for democratic process
Provide infrastructure that allows users to articulate and investigate values that are of greatest importance to them
Fairness (and specifically freedom from bias)
As far as we are able, do not privilege one mode of transportation, policy, etc over another
Transparency

27. Example Stakeholder Values
Clean air
Economic growth
Housing affordability
Individual property rights
Low taxes
Open space preservation
Social equity
Transportation options for disabled people
Walkable neighborhoods

28. Stakeholder Values (2) Stakeholder values may be in conflict
A particular choice or weighting of these values should not be built into the system
Being able to answer questions about certain stakeholder values may have significant design implications (e.g. biodiversity)

29. For more information
UrbanSim project website: Contact information: Alan Borning