Well, parent could be correct.<p>Just yesterday there was a post on here about London&#x27;s bus numbers, those had been inherited from the horse and cart days, been used on horse drawn trams, been used on electric trams, been used on trolleybuses (trams with little rubber wheels instead of proper steel ones) and now used on regular bus routes. Seems that London upgraded transport stock to get rid of trams without there being some huge conspiracy. A plausible scenario could happen elsewhere.