From visiting Amsterdam, the bicycle lanes are well designed for bicycles. Even when crowded, staying in the correct lane seems to work well. Pedestrians on the sidewalk, bikes in the bike lane, cars in the car lane (plus the light rail). Signals and crossing are designed so all 3 user groups can get where they need to go.
In the US, where most bike lanes are half-assed attempts (no physical separation, no signals, poorly conceived traffic crossings at turn lanes), a crowded bike lane quickly becomes unusable and bikes spill into the traffic lane.
In the US, where most bike lanes are half-assed attempts (no physical separation, no signals, poorly conceived traffic crossings at turn lanes), a crowded bike lane quickly becomes unusable and bikes spill into the traffic lane.