Journal Article

Bicycle Infrastructure and Traffic Congestion: Evidence from DC’s Capital Bikeshare

Jun 9, 2017 | Timothy L. Hamilton, Casey J. Wichman


Urban bike sharing is gaining popularity for its purported health, environmental, and traffic congestion benefits. Evidence from Washington, DC, one of the most congested US cities, suggests that the Capital Bikeshare program reduces traffic congestion.

Key Findings

  • A causal effect exists between the introduction of bike-sharing programs and traffic congestion. Findings show a reduction in DC traffic congestion upwards of four percent that can be attributed to the presence of a Capital Bikeshare station.
  • A secondary finding is that congestion reductions are concentrated in areas of high congestion.
  • The interactions among bicycle infrastructure and other modes of transit are only going to become more relevant as Washington, DC, and other cities expand their bike-sharing programs.


This study explores the impact of bicycle-sharing infrastructure on urban transportation. Accounting for selection bias in a matching framework, we estimate a causal effect of the Capital Bikeshare on traffic congestion in the metropolitan Washington, DC, area. We exploit a unique traffic dataset that is finely defined on a spatial and temporal scale. Our approach examines within-city commuting decisions as opposed to traffic patterns on major thruways. Empirical results suggest that the availability of a bikeshare reduces traffic congestion upwards of 4% within a neighborhood. In addition, we estimate heterogeneous treatment effects using panel quantile regression. Results indicate that the congestion-reducing impact of bikeshares is concentrated in highly congested areas.