The big difference is that when you have a collision at a 4-way or 2-way stop, it is almost always a "T-Bone" collision, where all the energy hits at a right angle. These collisions kill, especially at speed.
A similar collision on a roundabout is almost always a "glancing" blow, at an angle, and rarely causes injury or death.
Roundabouts force you to slow down when approaching. Stop signs can be ignored. Roundabouts can't.
These are extremely uncommon events, and when they do occur, the driver’s consumption of alcohol and/or methamphetamine is often a contributing factor.
A similar collision on a roundabout is almost always a "glancing" blow, at an angle, and rarely causes injury or death.
Roundabouts force you to slow down when approaching. Stop signs can be ignored. Roundabouts can't.