Rational plans meet real power: Twenty years of cycling infrastructure in Cambridge MA

The implementation of cycling infrastructure may seem like a technical planning exercise, yet in practice it is shaped heavily by shifting power relations. This paper examines the recent history of separated bike lanes in Cambridge, Massachusetts, a relative leader among U.S. cities in the development of separated cycling infrastructure. Using geospatial analysis of all bike lane projects from 2004 to 2024 and the case study method informed by 23 interviews (11 semi-structured and 12 exploratory) with key stakeholders, we identify the factors that determined whether projects advanced, stalled, or provoked opposition. We find that project trajectories reflected four stages of the local power balance: opportunism, ad-hoc community requests, legislative formalization, and backlash (“bikelash”). City staff exercised soft power by preparing network plans and technical standards, which defined the menu of viable options. Advocacy groups converted public support into legal mandates, while business associations and residents mobilized to slow down or reverse implementation. The findings highlight the interplay between hard political power and the soft agenda-setting power of planners. Lessons from Cambridge extend to other contentious sustainability transitions, suggesting that the delivery of climate adaptation and mitigation projects will depend less on rational technical plans than on how power is mobilized, contested, and institutionalized.