Measuring Factors That Impact Transportation Choices
A trio of papers that look into transit ridership and the factors influence the decisions on how to get from here to there have been added to the Best Practices section.
While housing is generally the focus of transit-oriented development discussions, job centers are equally important, according to a paper by Robert Cervero, professor and chair of the Department of City and Regional Planning at the University of California, Berkeley.
"In the end, concentrating housing near rail stops will do little to lure commuters to trains and buses unless the other end of the trip—the workplace—is similarly convenient to and conducive to using transit.," Cervero concludes.
In California, central business district office workers with rail stations nearby are nearly three times more likely to commute by transit than workers in decentralized employment centers. Factors such as trip-chaining, especially for child care, and the absence of restaurants and retail shops near suburban offices deter transit-commuting, according to Cervero. Flexing parking standards, introducing high-quality feeder buses and initiating workplace incentives such as deeply discounted transit passes are strategies that will boost transit's share of the commute trips.
The growing interest in creating more "livable" communities in which destinations are brought closer to home and work raises the question: How close is close enough? Using travel survey date from the Twin Cities region, this report by Michael Iacono, Kevin Krizek and Ahmed El-Geneidy examines different types of destinations and estimates distance decay models for auto and non-auto travel.
"How can we know if the 'one quarter mile assumption' that has become conventional wisdom in planning and designing communities is reliable? How far will bicyclists travel to cycle on a bicycle only facility? How far do people drive for their common retail needs? This research provides evidence on these and other closely related questions," the report asks.
The study found as much as a third of pedestrian trips exceed the often-cited threshold of one-quarter mile, regardless of trip purpose. On the other hand, bicycle travel was very dependent on trip purpose. Acceptable travel distances to work or school were much longer than shopping, recreation and entertainment trips by bike.
While the results were restricted to a relatively small sample area of the Twin Cities in Minnesota, the techniques should be scalable to larger geographic areas, according to the report's authors.
The goal of this paper by Brian D. Taylor and Camille N.Y. Fink of the UCLA Institute of Transportation Studies is to review the literature on explaining transit ridership, critique the sometimes significant weaknesses in previous studies, draw conclusions from the more rigorous studies on the factors which most influence transit use and recommendations on the steps needed to better understand and explain transit ridership.
"[T]ransit ridership is largely, though not completely, a product of factors outside of the control of transit managers," the study found. "Among these factors that transit systems do control, the quality of transit service and adroit pricing of transit services to target particular travel markets have proven most effective."
While transit agencies don't have control over many factors influencing ridership, the adoption of policies by other agencies that "encourage drivers to fully compensate society for the externalities of private vehicle use would likely cause people to become more judicious in their use of private vehicles, and in metropolitan areas, would make public transit service relatively more attractive to auto users," the report concluded.