[jimjamuser]

Originally Posted by Maker

How can they crash?

Way #1
The 3:00 car enters the rab already moving. Trivial to reach 20mph. Car did yield (was not required to stop) since they are watching traffic, see just that one other car in the inside lane, and safely enter the rab not next to that car with spacing.
The inside car exits across the path of the 3:00 car.

Way #2
Both cars traveling with a reasonable gap between them. Car on the inside lane slows down to make the exit "safer" by checking their mirrors. Then exits in front of outside lane car.

Way #3
Car in outside lane is not from the entitled TV population and is expecting a car in the inside lane to USE TURN SIGNALS, and they fail to do so.

Way #4
There is a third car in the inside lane. First car exits rab, and the car in the outside lane brakes to avoid a collision. The car following the outside lane exits very close the back of the car braking because they expected that car to move at the same speed. Exiting car brakes to avoid hitting the rear of that breaking car. But there is a 4th car, it's in the outside lane. Reaction time kicks in and by the time they brake to avoid the mess ahead, that 3rd car exits, crashing into them.

All cars are following all signs, all posted how-to-drive maps, all recommended "safe" advice from our keyboard experts.

BUT
If the outside lane must exit at every side road. (barriers prevent going around)
The only way to go around (pass a side road) is via the inside lane.
There would be none of this endless debates. Crashing at the rab exits would not be possible in any scenario because there would be no lane with vehicles to crash with.

OK, I believe you, but would it not be simpler to just have only one lane inside the roundabout? And do the merging before getting to the roundabout.......easy peasy, as they say.