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DRIVING AND THE BUILT ENVIRONMENT: THE FFECTS OF

COMPACT DEVELOPMENT ON MOTORIZED TRAVEL, ENERGY USE,

AND CO2 EMISSIONS

Briefing, U.S. SenateAugust 31, 2009

Transportation Research BoardDivision on Engineering and Physical Sciences

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IMPETUS FOR STUDY and

SPONSOR

• Requested in Section 1827, Energy Policy Requested in Section 1827, Energy Policy Act of 2005Act of 2005

• Funding provided by U.S. Department of Funding provided by U.S. Department of Energy in 2007Energy in 2007

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STUDY CHARGE and SCOPE

ChargeCharge: To examine the relationship between land : To examine the relationship between land development patterns and motor vehicle travel in development patterns and motor vehicle travel in the U.S. and assess whether petroleum use and the U.S. and assess whether petroleum use and COCO22 emissions could be reduced by changes in emissions could be reduced by changes in

development design.development design.

FocusFocus: Metropolitan areas and personal travel: Metropolitan areas and personal travel

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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

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Committee on the Relationships Among Development Patterns, Vehicle Miles Traveled, and Energy Consumption

José A. Gómez-Ibáñez, Chair, Harvard University, Cambridge, MassachusettsMarlon G. Boarnet, University of California, IrvineDianne R. Brake, PlanSmart NJ, TrentonRobert B. Cervero, University of California, BerkeleyAndrew Cotugno, Metro, Portland, OregonAnthony Downs, The Brookings Institution, Washington, D.C.Susan Hanson, Clark University, Worcester, MassachusettsKara M. Kockelman, The University of Texas at AustinPatricia L. Mokhtarian, University of California, DavisRolf J. Pendall, Cornell University, Ithaca, New YorkDanilo J. Santini, Argonne National Laboratory, Argonne, IllinoisFrank Southworth, Oak Ridge National Laboratory, Tennessee, and Georgia Institute of Technology, Atlanta

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KEY CONCEPTS

COMPACT, MIXED-USE DEVELOPMENT: COMPACT, MIXED-USE DEVELOPMENT: Land use patterns that increase the density, mix of Land use patterns that increase the density, mix of uses, contiguity, connectedness, and pedestrian uses, contiguity, connectedness, and pedestrian orientation of developmentorientation of development

Location matters – high residential density in the Location matters – high residential density in the middle of nowhere yields few benefitsmiddle of nowhere yields few benefits

Compact, mixed-use development Compact, mixed-use development ≠ multifamily ≠ multifamily housing only– small-lot, single-family housing only– small-lot, single-family development can yield benefitsdevelopment can yield benefits

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STUDY APPROACH

• Literature review

• Five commissioned papers

• Informational briefings

• Scenario development to quantify effects

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FINDINGS

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

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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.

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FINDINGS (cont’d)

Finding 3: More compact, mixed-use development can produce reductions in energy consumption and CO2 emissions both directly and indirectly.

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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.

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SCENARIO ASSUMPTIONSSCENARIO ASSUMPTIONSBASE CASE SCENARIO 1 SCENARIO 2

New & replacement hsg units (millions)

2030: 46-572050: 62-105

Same as base Same as base

Density of new development

Same as current 25% is twice as dense

75% is twice as dense

VMT per household

Current(21,187 mi/yr)

12 % lessif twice as dense

25% lessif twice as dense

Fuel/VMT New car 35 mpg (28 mpg on road) by 2020, improving slowly thereafter

Same as base Same as base

CO2/Fuel Current Same as base Same as base

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Finding 4Finding 4 (cont’d) (cont’d)

Bottom Line Estimate: Bottom Line Estimate: Reduction in VMT, Reduction in VMT, Energy Use, and COEnergy Use, and CO22 emissions from more emissions from more

compact, mixed-use development in the compact, mixed-use development in the range of <1 % to 11 % by 2050.range of <1 % to 11 % by 2050.

Committee disagreed about plausibility of Committee disagreed about plausibility of extent of compact development and policies extent of compact development and policies needed to achieve high end estimates.needed to achieve high end estimates.

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FINDINGS (cont’d)FINDINGS (cont’d)

Finding 5Finding 5:: Promoting more compact, Promoting more compact, mixed use development on a large scale will mixed use development on a large scale will require overcoming numerous obstacles.require overcoming numerous obstacles.

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FINDINGS (cont’d)

Finding 6: Changes in development patterns entail other benefits and costs that have not been quantified in this study.

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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.

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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.

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HOW TO ACCESS THE REPORT

Report, report summary, and commissioned papers are available

athttp://www.TRB.org/Publications/Public/Blurbs/162093.aspx

QUESTIONS?