Cost-benefit analysis is a tool frequently used in project appraisal to justify the implementation of infrastructures. Due to insufficient recorded data, the construction costs and safety benefits of urban bicycling infrastructure are difficult to estimate, weakening the appraisal and implementation of such projects. In this research, we conducted a study in Zurich to estimate construction costs and safety benefits of a city-wide cycling network, and showed that such a network has a high benefit-cost ratio (between 9 and 31).