Unintended greenhouse gas consequences of lowering level of service in urban transit systems

Julia B. Griswold, Han Cheng, Samer Madanat, Arpad Horvath

    Research output: Contribution to journalArticle

    Abstract

    Public transit is often touted as a 'green' transportation option and a way for users to reduce their environmental footprint by avoiding automobile emissions, but that may not be the case when systems run well below passenger capacity. In previous work, we explored an approach to optimizing the design and operations of transit systems for both costs and emissions, using continuum approximation models and assuming fixed demand. In this letter, we expand upon our previous work to explore how the level of service for users impacts emissions. We incorporate travel time elasticities into the optimization to account for demand shifts from transit to cars, resulting from increases in transit travel time. We find that emissions reductions are moderated, but not eliminated, for relatively inelastic users. We consider two scenarios: the first is where only the agency faces an emissions budget; the second is where the entire city faces an emissions budget. In the latter scenario, the emissions reductions resulting from reductions in transit level of service are mitigated as users switch to automobile.

    Original languageEnglish (US)
    Article number124001
    JournalEnvironmental Research Letters
    Volume9
    Issue number12
    DOIs
    StatePublished - Dec 1 2014

    Fingerprint

    Automobiles
    Budgets
    Greenhouse gases
    greenhouse gas
    Gases
    Travel time
    Elasticity
    automobile
    travel time
    Costs and Cost Analysis
    Railroad cars
    Switches
    footprint
    elasticity
    services
    Costs
    cost

    Keywords

    • greenhouse gases
    • optimization
    • public transportation
    • transit demand

    ASJC Scopus subject areas

    • Renewable Energy, Sustainability and the Environment
    • Environmental Science(all)
    • Public Health, Environmental and Occupational Health

    Cite this

    Unintended greenhouse gas consequences of lowering level of service in urban transit systems. / Griswold, Julia B.; Cheng, Han; Madanat, Samer; Horvath, Arpad.

    In: Environmental Research Letters, Vol. 9, No. 12, 124001, 01.12.2014.

    Research output: Contribution to journalArticle

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