> 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's the argument I keep hearing, but I'm not sure I buy it. Fewer people might be injured physically but even low speed accidents can cost thousands in repairs if not total your car, so going from a few people being hurt a year to multiple people losing their cars or being forced to pay out thousands every few weeks doesn't seem like a win to me.