A recent article in the journal Transportation analyzes the variation in bike commuting in large American cities, with a focus on assessing the influence of bike paths and lanes on bike commute rates.  Using new data on the total length of such bikeways in 90 cities and applying various statistical analysis methods, the study finds thatcities with a greater supply of bike paths and lanes have significantly higher bike commute rates, even when controlling for land use, climate, socioeconomic factors, gasoline prices, public transportation supply, and cycling safety.  The analysis also revealed that cities with safer cycling, lower auto ownership, more students, less sprawl, and higher gasoline prices had more residents cycling to work. By comparison, annual precipitation, the number of cold and hot days, and public transport supply were not statistically significant predictors of bike commuting in large cities.