If they regard the entrance as a road, how do they do it legally? What legislation empowers them to do that? As it stands the entrance is just a lowered kerb driveway.

The Traffic Signs Regulations and General Directions 2002 states: Box junction means the area of carriageway marked with yellow cross-hatching at a junction between two or more roads… Yellow box junctions seem to apply specifically to road junctions. How does TFL validate PCNs issued with regard to yellow box junctions, outside fire stations, where no road junction is involved? Is there separate legislation, or regulations, regarding this and if so, can anyone let me know what they are?