We haven't done anything as elaborate as an actual V-ROW, but we have a highway traffic law that you must yield to a bus that's signalling it wants in or you get fined.

Haven't seen it enforced much or evidence of enforcement, but I try and follow that law - seems like other drivers do too.

Not as fancy or foolproof, but helpful for any bus on any road. :)

Other simplier way to enact your "everyone out of the pool" - "the "transit lane is too crowded" suggestion, though, would be to have overhead "enter" - "do not enter" red-x, green-arrows - V-ROW closed to all but buses when it's on.

Those, I figure, would be more effective than the "turn signal" law, although both are relatively easy enough to implement.