Over the past decade, cities around the globe have embraced cycling like never before. Streets once dominated by cars are now alive with two-wheeled commuters, cargo bikes delivering goods, and families riding to school. The Copenhagenize Index, the most comprehensive ranking of urban cycling friendliness, evaluates 100 cities on how far they’ve gone to make cycling safe, convenient, and appealing—from protected lanes and bike boulevards to parking garages and bikeshare programs.