Sorry it took so long, but here is one of my solutions. I really need to rework the scoring and requirements by testing a lot more. I didn't mean to make it so hard!
I didn't explain it anywhere, but currently, the scoring is based on how many times cars pass through their own nodes. So if cars slow down a lot because of merging with other busy roads or taking sharp turns, it adds up, reducing the score significantly. Avoiding sharp 90-degree turns is a lot easier said than done, especially with the current ramp mechanics and limited space.
Definitely not a perfect system, but I feel like it worked given the time constraints. I really tried to limit the scope of the game, and even though I had many other ideas, I stuck to my initial plan as long as it worked in practice.
Thanks again for sharing your experience with the game, really appreciate it!
