This study investigates how individual shopping travel behavior reshapes the format of our cisites using Agent Based Modeling and Simulation

1. A Story about “Sustainability”
How do we change the world
Jing (Eric) Du
2/17/2012

2. What is “Sustainability”?
“(Sustainability) is development that meets the needs of the
present without compromising the ability of future generations
to meet their own needs.”
-- United Nations, March 20, 1987
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Source: www.un-documents.net/wced-ocf.htm

3. “Mixed land use is critical to sustainability”
 Sustainable Urban Forms
– Neotraditional Dev. :mixed land use; diversity
– Compact City :mixed land use; density; diveristy; compact; tranportation
– Urban Containment :mixed land use; diversity; compact; transportation
 Mixed Land Use
– Diverse functional land uses in a given area
– Reduce auto-travel
– Economic, Environmental and Social benifits
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4. But the reality...
Page  4 Left to right: New York, East Lansing, Victoria

5. Why are most real world cities “unmixed”?
 “Traditional rigid zoning”
Page  5 Breheny 1993; Masnavi 2000; Beatley 2000; Wheeler 2002; and ...

6. But...are they right?
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7. Human Behavior
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8. A simple story: go shopping!
Attractiveness: size, price...
Distance
Income
Gravity model
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9. A simple story: go shopping!
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10. An Artificial World: parameters
Parameter Value Explanation
Grid 50*50 2,500 cells
Simulation time 200 200 ticks or steps
Initial number of households 200 ea
Initial number of stores 20 ea
α [0.0, 6.0] Parameter of gravity model
β [0.0, 6.0] Parameter of gravity model
Store operation expense N (0.2, 0.05) Follow a normal distribution
Store size Pareto (500000, 2) Follow a Pareto distribution
Household purchase N(500, 100) Follow a normal distribution
Initial store’s cash reserve size Set the initial cash reserve same as store size
Expand threshold 2*size If cash_reserve >2*size, then expand
Baseline 0.3*size If cash_reserve<0.3*size, then quit the market
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11. Snapshot: when α=1.0, β=[0.25, 6.0]
 Monte Carlo process
 50 artificial cities
 625 different parameter combinations
 31,250 simulations
 114 hours in two computers
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12. Does mixed land use really lead to less transportation?
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13. Less transport due to the increase of walkability?
Transportation
5000
4500
4000
3500
3000
2500
2000
1500
1000
500
0
0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5 2.75 3 3.25 3.5 3.75 4 6
Walk distance Total distance Car distance
- The freqency of auto-travel doesn’t decrease;
- The frequency of nonauto-travel doesn’t increase;
- But the distance of each auto-travel is significantly reduced.
- Proved by many emperical studies (Kitamura et al. 1997; Boarnet and Sarmiento 1998; Boarnet and Crane 2001)
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14. Impacts of human behaviors on urban form?
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15. Impacts of human behaviors on auto-travel needs?
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16. Impacts of human behaviors on walkability?
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17. Why do most cities today have concentric areas?
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18. Why do most cities today have concentric areas?
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19. Lessons learned?
 Mixed land use can lead to less transport
But it’s attributed to the reduction of each
auto-travel distance, instead of the
increase of walkability
 Human behavior shapes our city: The
improvement of transportation technology
and efficiency makes people willing to
drive, and in turn today’s cities are more
“concentrated”
 Sustainability is a complex issue
 The application of computer simulation
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20. Discussion
Behavior
Environment
Society
Economy
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21. dujing@msu.edu
(517) 599 0486
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