That's not a contradiction. There's also a separate scheme to reduce London pollution (LEZ), and there's an extension of it currently starting up (ULEZ). They h

That's not a contradiction. There's also a separate scheme to reduce London pollution (LEZ), and there's an extension of it currently starting up (ULEZ). They have overlapping aims. For example, bus lanes were made for busses, despite cyclists and motorcycles (on most red routes) being able to enter them.