From what I understand roundabouts make accident rate go up, it is the severity of accidents that goes down which probably still a positive.
That said I have yet to drive through a roundabout that I think improved an intersection in any meaningful way. Half of them work as intended but I find them less pleasant to drive through, the other half are just horribly designed and often have semitrucks go through them when they aren't really large enough for that.
The problem is that at intersections the normative behavior of American drivers is to queue and wait for your turn. Roundabouts assume a different behavior based on jumping the line.
Thus there is a lot of unpredictability regarding other drivers due to generations of driving patterns developed in diverse regional driving cultures...many of which are distinctly not-urban.
In addition, this roundabout is part of an Interstate Highway interchange. The US Interstate system is at a scale that doesn't occur elsewhere. It is transcontinental.
Build more roundabout and make supervised self driving mandatory installs on all new cars. Watch both the accident rate and the time to destination improve
The US has been building roundabouts for about 30 years.
It has a lot of intersections.
Reconfiguring intersections is expensive and disruptive. Stop signs and traffic lights take less space and are often the simplest thing that might work.
That said I have yet to drive through a roundabout that I think improved an intersection in any meaningful way. Half of them work as intended but I find them less pleasant to drive through, the other half are just horribly designed and often have semitrucks go through them when they aren't really large enough for that.