I like it, cool concept! It seems like vehicles can accumulate out of the screen range? Not completely sure but if so, I'd suggest that when it happens a number or sign shows you that, to kinf of get your attention to the side affected.
Other than that it's nice, the game having audio even if just some background music could already improve a lot, but you have already mentioned that in the comments, you can always add it after the jam if you wicsh to polish it.
Cheers! ;)