OpenStreetMap

Good question -
OS OpenMap Local (April 2023) and some of the bus stops call it "Hog's Back", which is the name I would expect the A31 to have here.

I expect one goes to Farnham, and one goes to Guildford.

I have changed these to "Hog's Back" which is what it's known as locally, and is also what OS Local says, as well as older maps. I travelled along here today and didn't see any evidence of the Guildford Road/Farnham Road names.

The previous names had a "source:name" of OS Locator - I suspect there may have been an error or misinterpretation here.