It looks to me like everything tagged road is actually about a road bike. Much of road-bike is also tagged "road", even... These tags look redundant to me, and it'd be nice to get everything that's about road bikes to be tagged consistently...
This is a taxonomy question, really... Do we want to merge those and make "road-bike" a synonym for "road"? It seems like on a bicycling site the "bike" part of the tag is redundant, so my personal opinion to leave "road" as the tag that stays around. (besides, "road" is the more popular tag)
Do we think we'll need to be tagging about roads themselves (the surface bikes and other vehicles roll on)? Would "roads" or "streets" or "asphalt" or "concrete" work for those if they do come up?