This is remarkably well-made for a game jam, congrats! Everything looks and plays clean, and it feels like a professional product. As someone else pointed out, the road drawing mechanics feel a lot like Mini Motorways, and the graphics & pop SFX are also reminiscent of that game.
I’m also impressed at the number of puzzles you fit into the game. I did up to Level 4, but there are loads more I haven’t done yet. Even completed puzzles have replay value, I think - I did a pair of roundabouts for that last puzzle, but the cars are really slow at merging, so I bet I could make it more efficient.
Awesome job with this one! I really got lost in the zone.