Roundabouts depend on self-government. Drivers just need to follow a few simple rules: give way to traffic coming from the right; don’t get on the roundabout unless you can get off; signal left or right before you get on; signal left before you come off.
If the rules are followed, roundabouts prevent gridlock at busy times, without slowing down traffic the rest of the time.
Lately though, people seem to have forgotten how to use roundabouts. Maybe they weren’t told the rules; maybe they are used to different rules; maybe they don’t think the rules apply to them, or at least not right now, when they are in a hurry.
The problem is that if roundabout culture continues to change in this way, we will lose self-governance. Roundabouts will be replaced by traffic lights, and make things worse for everyone.
This is how culture changes. Gradually, almost imperceptibly, through daily usage, until the system has to be re-shaped around it.
For good or bad, we should at least do this with awareness, and perhaps even on purpose.