It's one of those horrible Reliant three-wheelers, not a Robin - more likely a Regal
You can blame WW2 for them too. A load of army types got motorcycle licenses during WW2 but no car or truck license, and you could (still can) drive a three-wheeler up to a certain weight limit on a motorcycle license. Slightly cheaper tax and insurance, cheaper to run, but a positive liability if you try to turn a corner at speed where they make a jeep look like a paragon of stability.
http://pages.zoom.co.uk/elvis/regal.html