Graphic Detail: Using Heatmaps to Explore Capital Bikeshare Data

Alexander Din
Maryland Department of Housing and Community Development

Capital Bikeshare is the major bikeshare system for the Washington, D.C. area. The network has more than 4,300 bicycles that serve commuters, tourists, and others who are interested in using a bicycle to travel. In 2017, more than 3.7 million trips were made using the Capital Bikeshare service. With so many observations (trips), the best visualizations are necessary to explore and make sense of the data. In this article, I demonstrate how to use heatmaps to get an overview of the data.

A heatmap is a shaded matrix that displays values via a graduated color scheme. The greater the number of observations binned into each category in the matrix, the greater the display color. By binning the data, some precision is lost but clarity may be made of a large dataset. The heatmap is a visualization that may show clusters or dispersion in the data. Results from exploratory analysis and visualization can answer basic questions about the data or provide insight how to further examine the data.