Andy Cotugno examines the relationship between land development patterns and motor vehicle travel in the U.S. and assess whether petroleum use and CO2 emissions could be reduced by changes in development design. Mr. Cotugno reveals how compact and mixed use development, and residential density directly correlate to a healthier environment, while acknowledging the challenges of economic and political reform.
Driving and the Environment: The Effects of Compact Development on Motorized Travel Energy Use and C02 Emissions
1. 1 DRIVING AND THE BUILT ENVIRONMENT: THE EFFECTS OF COMPACT DEVELOPMENT ON MOTORIZED TRAVEL, ENERGY USE, AND CO2 EMISSIONS September 1, 2009 Transportation Research Board Division on Engineering and Physical Sciences Of the National Research Council Andy Cotugno, Metro Congress for New Urbanism Transportation Summit November 4-6, 2009
2. 2 STUDY CHARGE and SCOPE Charge: To examine the relationship between land development patterns and motor vehicle travel in the U.S. and assess whether petroleum use and CO2 emissions could be reduced by changes in development design. Focus: Metropolitan areas and personal travel
3. 3 Committee on the Relationships Among Development Patterns, Vehicle Miles Traveled, and Energy Consumption José A. Gómez-Ibáñez, Chair, Harvard University, Cambridge, Massachusetts Marlon G. Boarnet, University of California, Irvine Dianne R. Brake, PlanSmart NJ, Trenton Robert B. Cervero, University of California, Berkeley Andrew Cotugno, Metro, Portland, Oregon Anthony Downs, The Brookings Institution, Washington, D.C. Susan Hanson, Clark University, Worcester, Massachusetts Kara M. Kockelman, The University of Texas at Austin Patricia L. Mokhtarian, University of California, Davis Rolf J. Pendall, Cornell University, Ithaca, New York Danilo J. Santini, Argonne National Laboratory, Argonne, Illinois Frank Southworth, Oak Ridge National Laboratory, Tennessee, and Georgia Institute of Technology, Atlanta
4. 4 KEY CONCEPTS COMPACT, MIXED-USE DEVELOPMENT: Land use patterns that increase the density, mix of uses, contiguity, connectedness, and pedestrian orientation of development Location matters – high residential density in the middle of nowhere yields few benefits Compact, mixed-use development ≠ multifamily housing only– small-lot, single-family development can yield benefits
7. 7 FINDINGS Finding 1:More compact development patterns are likely to reduce VMT.
8. 8 FINDINGS (cont’d) Finding 2:The most reliable studies estimate that doubling residential density across a metropolitan area might lower household VMT by about 5 to 12 percent, and perhaps by as much as 25 percent, if coupled with higher employment concentrations, significant public transit improvements, mixed uses, and other supportive demand management measures.
9. FINDINGS (cont’d) Double Density = 5-12% Design = add 3% Diversity (land use mix) = add 5% Density+Diversity+Design = 13% Population Centrality = 15% All Built Environment Variables = 25% 9
10. 10 FINDINGS (cont’d) Finding 3:More compact, mixed-use development can produce reductions in energy consumption and CO2 emissions both directly and indirectly.
11. 11 FINDINGS (cont’d) Finding 4:Significant increases in more compact, mixed-use development result in only modest short-term reductions in energy consumption and CO2 emissions, but these reductions will grow over time.
13. 13 SCENARIO ASSUMPTIONS 1970 Suburban Population = 54.5% 2000 Suburban Population = 62% Sources: National Resources Inventory (US Dept. of Ag.) and US Census
14. 14 Finding 4 (cont’d) Bottom Line Estimate: Reduction in VMT, Energy Use, and CO2 emissions from more compact, mixed-use development in the range of <1 % to 11 % by 2050. Committee disagreed about plausibility of extent of compact development and policies needed to achieve high end estimates.
15. 15 FINDINGS (cont’d) Finding 5:Promoting more compact, mixed use development on a large scale will require overcoming numerous obstacles: Local zoning, engineering and parking codes, housing preference
16. 16 FINDINGS (cont’d) Finding 6:Changes in development patterns entail other benefits and costs that have not been quantified in this study: infrastructure costs, social equity, health, neighborhood revitalization, transit feasibility, housing choice and price, farm land and wildlife habitat preservation
17. 17 RECOMMENDATIONS Recommendation 1: Policies that support more compact, mixed-use development and reinforce its ability to reduce VMT, energy use, and CO2 emissions should be encouraged.
18. 18 RECOMMENDATIONS (cont’d) Recommendation 2: More carefully designed studies of the effects of land use patterns and the form and location of more compact, mixed-use development on VMT, energy use, and CO2 emissions are needed to implement compact development more effectively.
19. 19 HOW TO ACCESS THE REPORT Report, report summary, and commissioned papers are available at http://www.TRB.org/Publications/Public/Blurbs/162093.aspx QUESTIONS? Andy.Cotugno@oregonmetro.gov