Oh yeah. Well spotted. Viewed from above, I can see why it would have looked like there was a gate and a driveway here, but no! In Mapillary it's very clear there is not! https://www.mapillary.com/app/?pKey=1513340519008372&focus=photo&lat=51.  https://www.openstreetmap.org/changeset/180006298 

But then further down the hill there *is* a gate: https://www.mapillary.com/app/?pKey=192737905917014&focus=photo , so it was probably surveyed and then the exact location confused.  That seems far more likely that there being a very new gate here. So I have removed the gate and also driveway from this location. We see a strip of tarmac of some sort here, but it's part of the playground ... and I have added a new gate and driveway at the other location: https://www.openstreetmap.org/changeset/180006298