Here is the DMV book for CA -
https://www.dmv.ca.gov/web/eng_pdf/dl600.pdf
and here is the DMV book for Virginia -
https://driving-tests.org/virginia/v...ndbook-manual/
The CA book does have a section on roundabouts - page 36.
Odd how one has many more pages than the other. Also, looks like the 2019 revisions for CA actually decriminalised refusing to give a blood test for DUI, though perhaps urine tests or breathalyser tests are allowed alternatives. In the UK refusing to be tested is an offence - though one is allowed a choice of tests I think.
In the UK it would often be impossible to do a U turn quickly because the roads are too narrow - even the wider ones, so generally banned.
Turn on red is not allowed in the UK, except if one has already decided to turn when there was a green light, in order to complete the movement - if safe to do so.
I rather liked 4 way stops, as they are - or should be - fairly safe. They do slow the traffic down. If they are busy they work rather like a roundabout, with an important difference - everyone gets a turn - if things work as they should. In the UK it is permitted to approach a roundabout at speed, and if there's a stream of traffic it can be very hard for cars from other directions to break into that.
Maybe in some states 4-way stops are less of a problem. There might be quite a lot in some cities in CA.
One problem with 4 way stops in the US is if drivers from other countries encounter them - as indeed I did when I first started to drive in the US. Drivers from the UK or Europe will stop (OK), but not know what to do next.
Some UK towns now have something called a road table. This is a 4 way area. Nobody has a clue what to do on those.
Love that! Bureaucracy doesn't always join up - probably different departments, and privacy laws prevented data exchange. Or just simply what we would call a cock up.
I liked the sign outside the airport in Boston, which said something like "In this state pedestrians always have right of way".
The consequences if they didn't .... doh .... though on the other hand pedestrians can be a nuisance if they misbehave.