You have to remember, OMSI has it's limitations. There's only so much a developer can do. But OMSI's limitations doesn't allow you to immediately have traffic avoiding specific hotspots, if there were gridlocks. You can only set various traffic rules, which also has it's limitations. I personally think from the way you described it, it's something that's out of a developer's control, simply from how OMSI is set up. I also think you have to take into account that in busy city maps, traffic lights are very common within a small vicinity. Having your traffic factor set to 100% will almost certainly cause a gridlock somewhere and will have a knock on effect to the surrounding roads and areas. Most OMSI maps have this issue. Even the default maps have the same issue.There is a lot to test here but you make a good point - when AI traffic is reasonably high (rush hour for example) then junctions should not deadlock themselves. I wish developers would sometimes (where necessary) omit some of the clever (nice to have) turning traffic if it results in traffic deadlocking - which renders the simulation unplayable.