Thanks for the feedback, I really appreciate it!
It's a good point that the turn signs and arrows are most interchangeable. I added the turn signs later in the development when I wanted to design levels where the player could cross the same place again but with a different result. That did mean they weren't really needed at all in the earlier levels though. It's interesting to hear that you found it more engaging with just those though, I might consider removing the arrows in that case!
The trial and error style wasn't quite what I was aiming for, so it would be good to address that too. I was thinking of having a button to demo the vehicle movement for a level, to see how it would play out without the risk of crashing into anything. I didn't manage to get round to that unfortunately, but it's something I could add if I update the game after the jam!
Thanks for letting me know about the UI scale issue too, I only ran it with a 1920x1080 viewport so didn't find that myself. I must have not set the scaling settings properly, so will look into that!