Cars on the circle should always have right of way and should never stop on the roundabout. Otherwise, wherever they intersect with another road they form little white lines/intersections and the cars stop on them, which completely negates the point of roundabouts. Cities: Skylines: Highway to hell, and the Great C. PSA to your PSA, because I see this happening all the time: Roundabouts are only roundabouts if you make them with highway roads.On my island interchange, I'd gone to some lengths to avoid this with flyovers and slightly more complicated on- and off-ramps. In a regular cloverleaf, the off-ramps are before the on-ramps, creating a weaving effect. The problem with a cloverleaf interchange is weaving: when some cars are trying to get off the highway and others are trying to get on, their paths can cross and end up in a horrible gridlock. The interchange started life as a standard cloverleaf interchange, which you can just plop down from the road menu. The only reasonable solution is to split up the traffic among several exits. There were just too many vehicles getting off at one ramp even when I got them to line up nicely, the sheer mass of cars going down the single-lane ramp created a constant accordion effect even though the line was constantly moving, every time someone braked or slowed down, a disruption would ripple down the entire line of cars, backing up traffic at the previous interchange.

Believe it or not, this kinda works! However, it's not optimal.

Cities skylines highway ramps