I went for a ride today and thought i'd put together a few clips showing how frequent roundabouts are in my country. I find them very usefull and safe, and it amazes me to hear so many Americans prefer four way stops over roundabouts. Stop signs would annoy the hell out of me.
It's really a matter of implementation. A good roundabout joins roads with vaguely similar levels of traffic, has a bit of elbow room, and presents the minimum impedance to traffic flow.
Here is a good local example. I've been through this on a bike a few times - there's enough traffic there that a stop sign for the east-west road butting into the north-south road would generate a nice traffic snarl, but a stoplight would be a bit much.
By contrast,
here's a stupid one (there's another one near the other end) grafted onto what was once a stop for the east-west road butting into the through road (it's how every other road butting into that north-south road works). Traffic there might be as high as 60 cars per minute during the morning and afternoon commute.
Might. It makes north-south traffic swerve to dodge the obstacle put up in the road. There's a freaking stop sign on the east-west road anyway. And in addition to having to yield to north-south traffic, someone stopped on the east-west road might need to back up to allow someone headed south to get around the traffic island. For some reason these were grafted into place and are far worse than just stop signs; suspect the neighborhood association got their hackles up about it being a through street and lobbied the city for them.
The three roundabouts
here are kind of marginal. They're spacious enough that one can smoothly blend into and out of them ... but also seemingly installed
just because. The third road on the north and south roundabouts is so minor that a more conventional bend with a stop sign on it should suffice. The middle one has recently seen a short road added going towards the lake to the west, but will see even less traffic than the other two due to obvious geographical limitations.