It's been legal for motorcyclists to use bus lanes in Plymouth, Devon for years and it works. It takes no time to travel through the city on a motorbike whatever the traffic. Strange though, 45 minutes ride up the road to Exeter, also in Devon and bikes are not allowed in bus lanes?
I remember riding a road somewhere in London on my way to The Ace Cafe many years ago. The outside lane was a taxi and motorcycle lane, I can't remember if buses used it too but it made for really easy progress for motorcyclist on a heavily congested road.