It’s nice to see modern traffic engineering coming to California.
“In a typical multi-lane roundabout, drivers freely shift between inner and outer lanes, delineated by painted lines. In a turbo roundabout, raised dividers separate the lanes. This means that when drivers merge onto the roundabout, they choose a lane — inner, center or outer — and stick with it until they peel off.”
That is not the case in a modern two-lane roundabout.
Incomplete in that it should say the only drawback to the turbos is that you can’t use the roundabout to make a u-turn, or circle around endlessly until you figure out which exit to take.