I think you need to spend a bit more time in the UK !
Take Hyde Park Corner for example. A bit of an extreme example as it is a super-busy roundabout. I will grant you that its not one where you will make smooth progress during peak rush-hour (outside of peak it works perfectly though).
There are also other good (and less extreme) examples along the secondary routes out of Heathrow (i.e. along Bath Road and Great West Road).
There's no way in hell you could replace any of the above with a US-style multi-way stop and achieve the same throughput of traffic.
Roundabouts work so well because you can have that magical combination of vehicles already established on the roundabout and also adding new vehicles all the time.
I think you need to spend a bit more time in the UK !
Take Hyde Park Corner for example. A bit of an extreme example as it is a super-busy roundabout. I will grant you that its not one where you will make smooth progress during peak rush-hour (outside of peak it works perfectly though).
There are also other good (and less extreme) examples along the secondary routes out of Heathrow (i.e. along Bath Road and Great West Road).
There's no way in hell you could replace any of the above with a US-style multi-way stop and achieve the same throughput of traffic.
Roundabouts work so well because you can have that magical combination of vehicles already established on the roundabout and also adding new vehicles all the time.