Funnily enough, the concept of a circular traffic junction - in a form similar to a roundabout today - was first introduced in Washington DC in the 1790s, including the Dupont Circle.
So literally speaking, you septics invented the roundabout traffic circle.
In about 1968, my dad drove round the roundabout in front of Buckingham Palace so us kids could get a better gander at the palace.
We got pulled over by a Bobby on the third circuit, and I kid you not, his first question was 'What's going on here, then?'
We were told if we wanted a better look, we would have to park the car and walk - like everyone else.
The answer to the question is 3.
The question I answered was 'why we have to register to vote'. We have to register to vote, because there is no law requiring you to register where you live - as opposed to Germany where they have 'Meldepflicht', which means you must register with the local authorities when you move. If there was something similar in the UK, then there would be no requirement to register, the necessary documents to vote would be sent automatically.
I haven't been in the army for, um, Holy cow! that many years!, but I still operate on '15 minutes before a parade'.