Signs are there in GSV September 2024, so newish, but failing to see signs like this really are a very significant motoring error, because a brief look at the GSV map, shows that part of Nightingale Lane is one-way only, hence the No Entry signs.
Was your father following satnav instructions ? Just as well there was no traffic around at the time he drove along there, as there could have been a head-on collision.