As per cp and others, the markings show it as a red route, as do the traffic signs.
The PCN, however, alleges a different contravention.
So to consolidate what I understand are the views:
Were you on a Red Route? Yes, if the markings and signs are correct.
Can the alleged contravention occur on a Red Route? No. This is not a parking place, it is a length of RR carriageway where the prevailing RR prohibition doesn't apply if the conditions on the sign are met.
You didn't = you were stopped on a Red Route, NOT in a loading/parking or any other type of place.
And if it's not a RR, then they can't use a camera.
Hey ho.