Two arm plates bolted together. Does not support the bike very well - note the bike is locked to a nearby railing
Bike ramp facility in Amsterdam. Exactly the same concept as a car parking ramp. High capacity and high usage.
Flying saucer shaped shelter. Provides some protection for bikes but makes access difficult. Also because the roof is not sloped dirt tends to accumulate on it.
This rack uses gravity to hold the bike firmly in place. Good idea, but many of the bikers apparently could not figure out how to use it properly.