A type of barrier designed to prevent (or discourage) illegitimate use of walking and cycling paths - in particular, entry using mopeds and motorcycles.
Typically these take the form of an 'A barrier', or 'K barrier', with added metal plates.
The latest Highways England standard states that these barriers must not be used at all, because they prevent access by various types of cycle, as well as other types of mobility aid, including wheelchairs and mobility scooters.
A frame and K Frame type barriers, often used to prevent motorcycle access, shall not be used on cycle routes because they cannot be negotiated by the cycle design vehicle.
Problems with illegal incursion - which these barriers frequently fail to prevent in any case - should be dealt with instead by enforcement.