[tooltower]

I didn't get from the article: are they better than all traffic signals, or signals with unprotected left turns? And what's a good vs. bad turnabout like?

I have had to go through a few that feel extremely dangerous compared to having all cars stop for me. So I know I must be missing something.

Edit: Also, I see a lot of comments on yield. I'm probably confused too, but how do they work when traffic is non-stop? Is there a specific traffic rate beyond which roundabouts become less safe?

[neuralRiot]

The thing is that a “yield” is not a “stop”, you have to match your pace to the circulating vehicles, similar as a highway “on-ramp” you don’t stop to let all the cars pass or slow down, that’s worst than speeding up and finding your space in traffic.

[Aloisius]

In California at least, the rules for entering a roundabout are to slow down when approaching, yield and prepare to stop to traffic in the roundabout and continue when there's a big enough gap in traffic to merge safely.

While in a roundabout, there's no passing permitted so you're essentially moving at the slowest vehicle's speed (which can be you). This rule can cause a problem if you're in the inner lane or a multilane roundabout and want to exit when a car is to your right when people don't choose their lanes properly when entering.

Highway merges have somewhat different rules in that you must be at or near the speed of traffic when merging instead of slowing down and you're not permitted to stop unless absolutely necessary.