It was common to allow a three wheeler on a motorcycle licence. The UK used to have a weight and engine limit and gave us Del Boy's Reliant Regal[1] and the Rob

It was common to allow a three wheeler on a motorcycle licence. The UK used to have a weight and engine limit and gave us Del Boy's Reliant Regal[1] and the Robin. One or two places, possibly including the US, required a motorcycle licence meaning you couldn't use a three wheeler on a car licence. More a relic of licencing history stemming all the way back to Morgan 3 wheelers and similar from the 20s and 30s[2]. Morgan actually recently re-introduced the classic 3 wheeler. You still find licence, tax, and insurance advantages to 3 wheelers despite them bearing little resemblance to the vehicles that led to the category. That said, the Smart car was a huge hit in Europe for size, parking and convenience so I don't see why a 3 wheeler couldn't still work. [1] https://en.wikipedia.org/wiki/File:Trotters.jpg https://en.wikipedia.org/wiki/File:Trotters.jpg [2] https://en.wikipedia.org/wiki/Morgan_3-Wheeler https://en.wikipedia.org/wiki/Morgan_3-Wheeler