There are fairly unified standards in new design, when there is road reconstruction.
The preference is a raised cycle track with physical buffer, that is below the height of the curb. (properly separating it from pedestrians)
Differences in design reflect:
a) The time at which a bike lane was implemented. (designs have evolved)
b) Whether the change is permanent or temporary ( generally flexipost and concrete barriers are interim or quick-build solutions that will be removed when the road is reconstructed. However, road reconstructions are every ~60 years. We would be waiting forever for cycling infrastructure if we insisted on the permanent version.
c) Road and Boulevard width. There isn't always enough room to deliver the ideal design. At that point you have to choose not to build a cycling facility at all, or do something a bit novel to make it work.