Today, the taxi is an even greater cause of slow flow in central London. Treated as "public transport" the cab is given all sorts of concessions. In reality it is a very selfish form of private transport and should be restricted accordingly.
Recently, I stood outside M&S (while my wife searched vainly inside for British-made goods) in east Oxford Street.
For the want of other diversion I counted taxis. Of 83 passing consecutively, 61 conveyed a single passenger. If that's not a misuse of precious roadway, tell me what is.
Here in Edinburgh, similarly, the taxi is treated with a respect it in no way deserves. An impediment to the development of adequate, speedy public transport (bus, tram or whatever) is the cab and our Transport high heid yins should act (and travel) accordingly.