Quantifying Transit's Impact on GHG Emissions and Energy Use: The Land Use Component

Higher density, mixed-use development and greater transit use can potentially contribute to reduced transportation-related greenhouse gas (GHG) emissions and energy use by facilitating shorter and fewer automobile trips and more non-motorized (i.e., walking and biking) trips. Transit may support compact land use by reducing the need for parking and roadway vehicle capacity, enabling clustered development, encouraging bicycle and pedestrian travel, facilitating trip chaining, and reducing household automobile ownership. The characteristics and magnitude of the interaction between transit and land use and the resulting changes in transportation-related GHG emissions and energy use may occur in different ways. For example, public transportation investments may precede land development and the resulting patterns of land use may have lower GHG emissions and energy use. This is the case with many rail expansions. Land use changes and public transportation investments may also occur interactively or synergistically and mutually reinforce each other. This research seeks to better understand both cases, and consequently has two objectives: first, to estimate the direct impact of transit on land use and the associated impacts on GHG emissions and energy use (such as the case of a project expansion); and second, to understand the interactive or synergistic impact of changes in transit and land use on GHG emissions and energy use. These are described in more detail in the Objectives section below. The American Public Transportation Association (APTA) has developed an approach for transit agencies to estimate the transportation-related GHG emissions displaced or avoided in a region (see Quantifying Greenhouse Gas Emissions from Transit, APTA Standards Development Program, approved August 2009). The APTA approach takes into account GHG emissions from transit and the GHG reductions from (1) mode shift to transit, (2) congestion relief, and (3) compact development patterns and reduced travel by automobile resulting from improved transit services. The most challenging component of the APTA methodology is this final component--estimating the land use-related impacts of transit and the associated potential decreases in automobile travel on transportation-related GHG emissions. A number of transit agencies have quantified the net impact of their services on transportation-related GHG emissions and energy use, including Chicago Regional Transportation Authority (Chicago RTA), Los Angeles County Metropolitan Transportation Authority (LACMTA), New York Metropolitan Transportation Authority (NY MTA), and Southeastern Pennsylvania Transportation Authority (SEPTA). While these transit agencies initiated their analysis subsequent to the APTA Standards Development referenced above, each adopted different approaches for measuring their transportation-related GHG emissions and energy impacts through land use. Although other transit agencies may seek this information, most lack sufficient resources to undertake similar analyses. Other significant research has been conducted on the linkage between transit, energy use, and GHG emissions. These studies have examined how the built environment affects vehicle miles traveled (VMT), GHG emissions, energy consumption, and other related topics. Examples of prior studies are included below in Special Note A. A gap in the research to date has been assessing the specific role of transit as a driver in reducing transportation-related GHG emissions and energy use through its effect on land use at the transit system, corridor, and project levels. Another gap exists regarding how changes in land use and transit systems occur interactively or synergistically and mutually reinforce each other to reduce GHG emissions and energy use. As such, there is a need to review current research, develop a methodology to quantify the transportation-related GHG emissions and energy use related to land use that can be attributed to transit, and evaluate the synergistic interaction between transit and land use and its effect on GHG emissions and energy use. This research is particularly important since the land use component may be a significant factor for transit's reduction of transportation-related GHG emissions and energy use. Transit agencies and other organizations are interested in measuring their net transportation-related GHG emissions and energy use for a variety of reasons. These include: (1) Understanding and measuring the full benefit transit provides to transportation-related GHG emissions and energy use through land use effects; (2)Measuring benefits of transit that historically have not been measured; (3) Compiling GHG inventories for climate registries; (4) Developing Climate Action Plans; (5) Complying with local legislation such as California's SB 375; (6) Communicating with Metropolitan Planning Organizations (MPOs); and (7) Improving MPO modeling and estimation of transit benefits. The results of this research are expected to assist transit agencies, state department of transportations (DOTs), MPOs, and others to better estimate the change in transportation-related GHG emissions and energy use related to altered land use patterns. The objectives of this research are to: (1) Develop a methodology to quantify the transportation-related GHG emissions and energy use related to land use changes that can be attributed to transit. The methodology developed shall quantify the impact of transit on land use and the resulting impact on transportation-related GHG emissions and energy use and shall determine what portion of land use related impacts, and thus changes in transportation-related GHG and energy use, are attributable to transit. (2) Identify, describe, and, to the extent possible, quantify the synergistic interaction between transit and land use and the effects on transportation-related GHG emissions and energy use.

Language

  • English

Project

  • Status: Completed
  • Funding: $400000.00
  • Contract Numbers:

    Project H-46

  • Sponsor Organizations:

    Federal Transit Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590

    Transit Cooperative Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC    20001
  • Project Managers:

    Schwager, Dianne

  • Performing Organizations:

    ICF Incorporated LLC

    9300 Lee Highway
    Fairfax, VA  United States  22031
  • Principal Investigators:

    Gallivan, Frank

  • Start Date: 20111011
  • Expected Completion Date: 0
  • Actual Completion Date: 20141201
  • Source Data: RiP Project 28916

Subject/Index Terms

Filing Info

  • Accession Number: 01543206
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project H-46
  • Files: TRB, RiP
  • Created Date: Nov 12 2014 1:00AM