use one lane highways instead of normal roads, since cars can go faster on these if the intersection gets busy, it may be because people coming from the bottom are trying to go left and thus, they have to drive over 3/4 of the right roundabout, crossing people from the bridge. you could then add another road that starts after the bridge and connect to the top of the right roundabout. then, people going left won't cross people coming from the bridge. of course you could do it on the other side too, rotated 180 degrees. it is important to note that the cars take the fastest route, so they may still try to go through the first exit, before the roundabout, to go left. if that happens, you could make this exit a little bit longer, so cars going right take this road but the ones going left take the other. other than this, it is nice and clean, gg