Hah! Have just received a sharp lesson in the fallibility of memory, even of a place I pass weekly!
I can only think I got confused by looking at too many archive photos when researching the matter:
The 'Drive In Question' has a stout screen of Leylandii blocking the view of the parallel path!
I can see the owner's point of view - to some extent. It's an awkward junction that didn't used to be there when the path was a railway line, and the drive belongs to a house that was 'squeezed in' at some point post-war. The rest of that side of the street is 1910 terrace.
Nevertheless, I think narrowing the entrance is only to swap one hazard for another, and suggests that the proper duty of care on the user of the drive is being downplayed. After all, the majority of house drives open onto pedestrian pavements, some of them quite busy, so the situation is not actually all that unusual.
I also note that a new 'Concealed Entrance' advisory sign has been erected for users leaving the path to join Inverness Road.