If you zoom in close you'll see NCC haven't actually drawn the pink line across the A11.  Looking at the definitive map (https://maps.norfolk.gov.uk/definitivemaps/TM19NW.pdf) you'll see NCC have a gap between the ends of FP 18 and 34, they don't join up.  The definitive statements say FP 18 meets the A11 and FP 34 starts (south of area 1682) at a gate into area 1681 (pasture). Neither path is said to join or cross the A11 road where the central and side crash barriers have no pedestrian gaps. 

These paths did join originally. When the A11 bypass was built part of FPs 18 and 34 were extinguished and FP 33 was created. You are still allowed to walk FP 34 but it's a dead end. The landowner is legally obliged to keep the way open but fails to do so. I did walk the path quite a few years ago.