I have not noticed a big difference in behavior between Louisville and Seattle urban drivers, either, with the exception of much greater respect in Seattle for pedestrians in crosswalks. The big difference lies in bicyclist behavior. In Seattle, the great majority of bicycle commuters appeared adept at commuting by bicycle. Regardless of their riding speed, they predominantly rode bicycles that fit them properly, wore helmets, and carried their belongings in sophisticated waterproof panniers. Most rode in work clothes rather than bicycling clothes, and few rode on fancy road bikes, though I saw plenty of high-quality commuting bikes.
Yesterday, I saw a downtown Louisville bicyclist riding with his seat much too low, crossing the street at a walking pace in the crosswalk, riding from one sidewalk to another, without a helmet. He would have stuck out like a sore thumb in downtown Seattle. In a 5-minute span well after dark last night, I saw two riders without lights, both on major streets (Brownsboro Road and Frankfort Avenue). Even with vastly more bicycle traffic, I never saw bicyclists in Seattle riding after dark without lights.
Somehow, the bicycling community in Seattle has learned from experience or taught one another how to ride safely and efficiently. I believe that this happens much more quickly as the proportion of serious cyclists in a community grows. As a city develops a discernible bicycling community, that bicycling community establishes social norms for its members. Social norms affect behavior more powerfully than any formal education or law enforcement programs.