1 DRIVING AND THE BUILT ENVIRONMENT: THE FFECTS OF COMPACT DEVELOPMENT ON MOTORIZED TRAVEL, ENERGY USE, AND CO 2 EMISSIONS Briefing, U.S. Senate August 31, 2009 Transportation Research Board Division on Engineering and Physical Sciences

2 IMPETUS FOR STUDY and SPONSOR Requested in Section 1827, Energy Policy Act of 2005Requested in Section 1827, Energy Policy Act of 2005 Funding provided by U.S. Department of Energy in 2007Funding provided by U.S. Department of Energy in 2007

3 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 CO 2 emissions could be reduced by changes in development design. Focus: Metropolitan areas and personal travel

4 NRC STUDY COMMITTEE PROCESS Formation of committeeFormation of committee Committee deliberationCommittee deliberation Preparation of draft reportPreparation of draft report Independent review of reportIndependent review of report Report publication and disseminationReport publication and dissemination

5 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

6 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

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9 STUDY APPROACH Literature review Five commissioned papers Informational briefings Scenario development to quantify effects

10 FINDINGS Finding 1: More compact development patterns are likely to reduce VMT.

11 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.

12 FINDINGS (cont’d) Finding 3: More compact, mixed-use development can produce reductions in energy consumption and CO2 emissions both directly and indirectly.

13 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.

14 SCENARIO ASSUMPTIONS BASE CASESCENARIO 1SCENARIO 2 New & replacement hsg units (millions) 2030: : Same as base Density of new development Same as current25% is twice as dense 75% is twice as dense VMT per household Current (21,187 mi/yr) 12 % less if twice as dense 25% less if twice as dense Fuel/VMTNew car 35 mpg (28 mpg on road) by 2020, improving slowly thereafter Same as base CO 2 /FuelCurrentSame as base

15 Finding 4 (cont’d) Bottom Line Estimate: Reduction in VMT, Energy Use, and CO 2 emissions from more compact, mixed-use development in the range of <1 % to 11 % by Committee disagreed about plausibility of extent of compact development and policies needed to achieve high end estimates.

16 FINDINGS (cont’d) Finding 5: Promoting more compact, mixed use development on a large scale will require overcoming numerous obstacles.

17 FINDINGS (cont’d) Finding 6: Changes in development patterns entail other benefits and costs that have not been quantified in this study.

18 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.

19 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.

20 HOW TO ACCESS THE REPORT Report, report summary, and commissioned papers are available at / aspx QUESTIONS?

21 SCENARIO RESULTS: VMT

22 SCENARIO RESULTS: FUEL

23 SCENARIO RESULTS: CO 2