@GTAbear ... finally! I tested your script on several junctions. My findings were similar to yours: Sometimes it works, sometimes it doesn't. The more cars the worse it gets. For example some cars/drivers "refuse" to follow to the designated target even though I pressed Num9 multiple times or held it. The front wheels are moving left to right and vice versa but they still don't accelerate.
I tried to combine it with Scene Manager to give general directions and move those cars, which don't comply, to the right direction using your script. But some of them still gave me a hard time. I'm afraid the AI is more "A" than "I" and forces me to give up some immersion. I'll have to stick with deleting some traffic via console or scripts (e.g. Scene Manager or Clean Up The Mess). If your want to keep working on your script, I'll keep testing and provide you with feedback but if your don't I'm totally fine with it.
In any case: Thanks a lot for your effort! 🙂👍