OP, you have driven past two quite clear "Flying Motorbike" signs that mean "No Entry for motorvehicles", and this means taxis as well. Are you new to taxi driving, because these signs are in place all over London, marking the entrances to Low Traffic Neighbourhoods, (LTNs). Whilst "The Knowledge" has to be passed to the Met Police's satisfaction, it doesn't mean you can pass signs like this.