California Environmental Protection Agency AIR RESOURCES BOARD THE LAND USE - AIR QUALITY L I N K A G E How Land Use and Transportation Affect Air Quality 1997 Edition Acknowledgments This report was prepared by the staff of the Air Resources Board's Office of Air Quality and Transportation Planning under the direction and review of Lynn Terry, Assistant Executive Officer, and Anne Geraghty, Manager of the Transportation Strategies Group. The principal author is Ms. Terry Parker, M.A., Associate Air Quality Specialist/Planner. The cover illustration was drawn by Mr. James Lertiz of the San Francisco office of Wallace, Roberts & Todd as part of the “Bay -Park Link Report” for the City of San Diego Planning Department. 1997 EDITION This update of the ARB’s Land Use/Air Quality Linkage Report presents a summary of information on linkages between transportation, land use and air quality. It incorporates new data that has become available since this report was first published in 1994, including results from three major ARB-funded research projects. It also provides several new California examples. THE LAND USE-AIR QUALITY LINKAGE CONTENTS INTRODUCTION The Linkages Vehicle Use and Air Quality......................................................... 1 Land Use and Air Quality ............................................................. 2 Modes of Travel ............................................................................ 3 OPTIMUM LAND USE STRATEGIES FOR AIR QUALITY .................................................................... 4 Community Strategies Enhanced Central Business Districts ................................................ 5 Clustered Activity Centers ................................................................ 6 "Shopping Centers" Study............................................................ 6 Compact Development...................................................................... 6 Density and Transit Ridership....................................................... 7 Employment Concentration ..........................................................10 Neighborhood Strategies Focused Infill and Renewal..............................................................10 Mixed-Use Developments................................................................11 Interconnected Street Patterns..........................................................11 Traffic Calming................................................................................12 Traditional Neighborhood Design ...................................................12 Transit-Oriented Development ........................................................13 COMMUNITY EXAMPLES Within California ...........................................................................14 Outside California ..........................................................................16 QUANTITATIVE RELATIONSHIPS ...................................................18 ARB-Sponsored Research..............................................................19 “Five Neighborhoods” Study .....................................................19 “Transportation-Related Land Use Strategies” Study ...............19 EMISSION REDUCTION BENEFITS ..................................................21 OTHER BENEFITS Fewer Automobile Expenses .........................................................21 Economic Advantages....................................................................21 Lower Infrastructure Costs.............................................................22 Diverse and Affordable Housing ...................................................23 CONCLUSION.......................................................................................23 SOURCES...............................................................................................24 THE LAND USE-AIR QUALITY LINKAGE LIST OF FIGURES Figure 1: Total Annual Vehicle Miles Traveled in California and Total State Population,1970-1995 ............................................... 1 Figure 2: Emissions Associated with Typical “Indirect” and “Stationary” Sources .................................................................. 2 Figure 3: Portion of Personal Trips Five Miles or Shorter - and Purpose of Trips.......................................................... 2 Figure 4: Modes of Travel in California, 1991.................................................... 3 Figure 5: Travel by Automobile and Transit in Four Metropolitan Areas Worldwide .................................................. 4 Figure 6: Travel Behavior at an Urban and a Suburban Regional Shopping Center ................................................................. 6 Figure 7: Minimum Densities to Support Various Levels and Types of Transit Service .................................................................... 8 Figure 8: Character of Residential Density (diagram). ...................................... 9 Figure 9: Interconnected and Isolated Street Patterns (diagram).......................11 Figure 10: Comparison of Characteristics: "Traditional Neighborhood Development" and Typical Suburban "Planned Unit Development" .............................................................12 Figure 11: LUTRAQ: Projected Transit and Walking Mode Shares in the year 2010; Four Alternative Scenarios ....................................17 Figure 12: Rates of Transit Use for Commuting in the S.F. Bay Area ...........................................................................18 Figure 13: Relationship Between Population Density and Annual Vehicle Miles of Travel per Capita .........................................18 Figure 14: Travel Modes in Five S.F. Bay Area Neighborhoods..........................19 Figure 15: Household Travel Characteristics in Sample California Communities ........................................................20 Figure 16: Infrastructure Costs in Relation to Residential Density .....................22 THE LAND USE-AIR QUALITY LINKAGE INTRODUCTION will continue to greatly improve air quality, large increases in population and driving The form and shape that growing cities take in partially offset the benefits of cleaner motor the next several decades will have an important vehicles. impact on the future air quality of California's major metropolitan areas. A growing body of During the past twenty years, the total number literature and research indicates that land use of "vehicle miles traveled" (VMT) in the state and transportation strategies can reduce vehicle has increased at a much faster rate than popu- trips and vehicle miles traveled, and thus help lation growth. We are driving more often and reduce the air pollution produced by auto- longer distances. mobiles. By creating environments that are more conducive to alternative transportation Between 1970 and 1995, total annual VMT in modes such as walking, biking and transit, we California more than doubled, increasing from can create more "livable" communities -- 103 billion to over 270 billion miles of travel communities with reduced congestion, per year (although the growth rate in VMT increased personal mobility, and cleaner, tapered off somewhat between 1990 and 1995). healthier air. Between 1970 and 1995, the state's population grew by 60 percent, increasing from 20 to 32 This report summarizes data currently available million people.2 on the relationships between land use, trans- portation and air quality. It also highlights strategies that can help to reduce the use of the Total Annual Vehicle Miles Traveled private automobile. And, it briefly summarizes and Population in California, 1970-1995 several research projects funded by the 300 California Air Resources Board (ARB). As Annual VMT new data becomes available, it will be added to 250 (in Billions) updated versions of this report. 200 Total State Population 150 (in Millions) THE LINKAGES 100 50 Vehicle Use and Air Quality 1970 1975 1980 1985 1990 1995 While dramatic improvement has been made, most of California's metropolitan areas still Figure 1 2 exceed state and federal air quality standards. This is true despite the reduction of air pollution from both mobile sources (cars, Half of the nation's ten most congested trucks and buses) and stationary sources metropolitan areas are located in California: (utilities and other industries). Los Angeles, San Diego, San Francisco, San Jose, and San Bernadino/Riverside.3 And Mobile sources produce more than one-half of traffic congestion in the State’s metropolitan all smog precursors and over 90 percent of the areas is expected to continue to worsen, carbon monoxide in the State's major urban especially during peak-hour commute periods. areas. Today's new cars pollute about 90 Delays cost personal time, and translate into percent less than models produced 25 years ago higher costs for businesses and consumers.4 due to California's strict vehicle emissions standards. By 2003, the average new car in California will pollute 75 percent less than 2 Calif. Air Resources Board, BURDEN 7F Emissions 1 1994 models. But, although these standards Inventory, 1994; and Calif. Dept. of Finance, 1996. 3 Urban Land Institute, Land Use In Transition, 1993. 1 Calif. Air Resources Board, Status Report, 1994. 4 U.S. Department of Transportation, 1996. A 1993 report by Governor Wilson’s Growth choose -- car, vanpool, bus, train or trolley, Management Council pointed out: walking, or bicycling. "California cannot support a population For example, vehicles traveling to and from a growing