Pedal cycles and pedestrians prohibited

TR220

Where: At the beginning of or entrance to a carriageway, lane or path.
Purpose: To prevent cyclists and pedestrians from using a certain road or a certain section of a road where they can cause a danger to themselves or other road users.
Action: Look out for cyclists and pedestrians who use the road despite the prohibition. Cyclists and pedestrians must follow a different route and may not proceed beyond this sign.

Manual on Road Traffic Signs, page 14.