OBJECTIVE: This study evaluates changes in physical activity and active transportation associated with installation of new bicycle boulevards. METHODS: This natural experiment study uses data from a longitudinal panel of adults with children (n=353) in Portland, OR. Activity and active transportation outcomes were measured with GPS and accelerometers worn for up to 5 days in 2010-11 and 2012-13. The effect of the treatment was estimated using difference in differences estimation and multivariate regression models. RESULTS: In five of the seven models, the interaction term was not significant, indicating that after controlling for the main effects of time and exposure separately, there was no correlation between being in a treatment area and minutes of moderate and vigorous physical activity (MVPA) per day, bicycling N10 min, walking N20 min, minutes of walking (if N20), or making a bike trip. Significant covariates included rain, being female, living closer to downtown, and attitudes towards bicycling, walking, and car safety. CONCLUSION: This study could not confirm an increase in physical activity or active transportation among adults with children living near newly installed bicycle boulevards. Additional pre/post studies are encouraged, as well as research on the length of time after installation that behavior change is likely to occur.