Browsing by Author "Cao, Jason X"

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    Catalysts And Magnets: Built Environment Effects On Bicycle Commuting
    (2015) Schoner, Jessica E; Cao, Jason X; Levinson, David M
    What effects do bicycle infrastructure and the built environment have on people’s decisions to commute by bicycle? While many studies have considered this question, commonly employed methodologies fail to address the unique statistical challenge of modeling such a low mode share. Additionally, self selection effects that are not adequately accounted for may lead to overestimation of built environment impacts. This study addresses these two key issues by using a zero-inflated negative binomial model to jointly estimate participation in and frequency of commuting by bicycle, controlling for demographics, residential preferences, and travel attitudes. The findings suggest a strong self-selection effect and modest contributions of bicycle accessibility: that bicycle lanes act as “magnets" to attract bicyclists to a neighborhood, rather than being the “catalyst" that encourages non-bikers to shift modes. The results have implications for planners and policymakers attempting to increase bicycling mode share via the strategic infrastructure development.
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    Intraurban Accessibility and Employment Density
    (2006-08-01) Iacono, Michael J; Cao, Jason X; Cui, Mengying; Levinson, David M
    This study investigates the relationship between urban accessibility and firm agglomeration, as reflected in patterns of urban employment densities. We use measures of accessibility derived from the regional highway network, combined with small-scale (Census block-level) data on employment from the Longitudinal Employer-Household Dynamics (LEHD) data set to generate proxies for different sources of agglomeration, specifically urbanization and localization economies. These variables are employed in a set of employment density regressions for 20 two-digit NAICS code sectors to identify the propensity of each sector to agglomerate in response to varying levels of accessibility. The density regressions are applied to sample data from the Minneapolis-St. Paul, Minnesota (Twin Cities) metropolitan region for the years 2000 and 2010. We find that in general urbanization effects tend to overshadow those of localization effects. Moreover, these effects tend to vary by sector, with many service-based sectors showing a stronger propensity to agglomerate than manufacturing and several "basic" sectors like agriculture, mining and utilities.