I used to work in Edinburgh a lot, and would get a taxi from the airport to the centre and back again most weeks.
Along the way way (Corstorphine Road????) there was a long section where the inside lane was a time limited bus/taxi lane. I don't think that I ever saw a private car in that lane, even when it was perfectly OK to be there.
Sometimes motorists either don't understand the restrictions, or are just creatures of habit.