spiregrain
This way, and possibly several others in the area are now being used for Autonomous vechicle trials.  Where the way is wide enough (two narrow 'lanes'), one lane is dedicated to an autonomous vehicle service of some sort.   It has a road marking including the word "SHUTTLE" - https://gateway-project.org.uk/preperation-begins-for-gateway-public-trials/ 

In other places, the 'shuttle' is to share the single lane with pedestrians and cyclists.   Nothing can go wrong, obviously.

Project details here:  https://gateway-project.org.uk/

I haven't tracked down a definitive map of SHUTTLE routes.   Not sure how to tag anyway.