That innocuous looking track heading South off the Western side of the road is, according to the Ordinance Survey map and East Riding Coucil, a boat. Well, actually not a boat, but a B.O.A.T. A Byway Open to All Traffic.
2.1. Section 66(1) of the Wildlife and Countryside Act 1981 defines a byway open to all traffic (“BOAT”) as:
“a highway over which the public have a right of way for vehicular and all other kinds of traffic, but which is used by the public mainly for the purpose for which footpaths and bridleways are so used”.
They are fairly rare, with only 18 in the whole of the East Riding, and are somewhat of a hangover from before the roads were tarmacadammmed and formally adopted by the Authorities. It is a real shame that this track was never adopted as a proper ordinary road as it heads due South before it rejoins the real road and neatly cuts out a big loop, and multiple bends. The reason why it was never adopted is lost in the mists of time.
For the avoidance of doubt, while you do have the right to drive along it, it is certainly not recommended, particularly in wet conditions, unless you have checked the map to be sure you don't stray from it and that you are absolutely sure you have a vehicle up to the task.
More information about this,and the other B.O.A.T s in the East Riding can be found at https://www.whatdotheyknow.com/request/east_riding_byways_open_to_all_t