Here’s a really fascinating animation and analysis of traffic flows with different intersection methodologies. More interesting is that they were done with off-the-shelf steam games/tools found on Steam. I think

Network Extensions 2
https://steamcommunity.com/sharedfiles/filedetails/?id=812125426

Traffic Manager: President Edition
https://steamcommunity.com/sharedfiles/filedetails/?id=583429740

Some interesting observations:

• 4 way intersections with lights (235 cars/min) is only slightly better than a no light free-for-all (191 car/min)
• Standard roundabouts with stops are really horrible, but get pretty interesting and good with a few simple improvements
• There’s a lot of interesting junction/interchange types I’ve never seen before