Student Research: What makes some CaBi stations more used than others?
Open trip data lets researchers analyze bike sharing systems in detail. They are making useful discoveries about how culture and urban spaces affect the way people use bikeshare. These conclusions can help cities refine their bikeshare systems as they grow and mature.
Expected monthly Capital Bikeshare ridership based on October 2011 usage.
Student Reseach: What makes some CaBi stations more used than others?
By David Dadido
My recently completed master's paper analyzes the factors behind the number of trips at different Capital Bikeshare stations. I created a regression of trips in October 2011 that began at stations in the District. After controlling for 14 variables, the analysis concludes that 5 key factors primarily determine a station's usage:
• The population aged 20-39
• The level of non-white population
• The retail density, using alcohol licenses as a proxy
• Whether Metrorail stations are nearby
• The distance from the center of the CaBi system
I measured each variable based on what's within a ¼-mile walk of each station. With that information, I created a "suitability map," above. For any spot in DC, it projects how much ridership a station would get if DC placed one there. You can also download the KML file to view the analysis in Google Earth.
The map shows that as you get farther from the main activity centers in central DC, there's a dramatic drop-off in station demand. Approximately 13% of Capital Bikeshare stations, as of March 2012, are located in areas where we would expect fewer than 18 trips a day. The actual usage data shows that a significant number of these stations at the edge of the system have even fewer trips.
There are equity reasons to place stations outside the core; policymakers want to make sure that money spent on Capital Bikeshare benefits more than just those who live and work in central areas, and it builds political support from council members representing wards farther away. However, there are multiple areas around the District that are under-served by bikeshare today, yet highly suitable under the analysis.
Planners and policymakers should consider these areas as they build out and tweak the system in the coming years. The figure below shows the coverage gaps by overlaying the existing bikeshare stations and the suitability map.
What can we conclude from this?
Visit http://greatergreaterwashington.org to learn what the Washington region and other cities should consider the following issues when they plan and expand their systems.
David Daddio is a master's student in the Department of City and Regional Planning at the University of North Carolina, Chapel Hill. Originally from Columbia, Maryland, David founded Rethink College Park while an undergraduate at the University of Maryland. He is currently the Second-Year Editor of Carolina Planning, the oldest student-run planning publication in the country.