All Lanes Must Exit

Will you like it?
Are you looking for a transportation sim that will scratch a particular itch in a very satisfying way for a few hours? This might be the game for you... Actually, just look at the pictures or watch the trailer and you'll pretty much know whether you'd enjoy it.
Your job in this game to design a highway interchange. Don't go over-budget and don't have traffic jams. Connect all the roads so that cars from every direction can get to every direction. Basically, all lanes must exit.
That price though...
Is it totally free? Yes, there are no in-app purchases or anything. Why is it free? I can't legally earn money from it right now, for reasons of international law. But feel free to assume it's because I'm being held hostage in a basement and my captors would pocket the money.
Gameplay details
The little cars have places to go! Using simple mouse-based controls, build a road network consisting of lanes and nodes that connects each incoming road to all of the outgoing roads. How you do that is up to your design skills and personal taste, as long as it handles all the traffic and doesn't cost too much. Cloverleafs, turbines, roundabouts, and braided interchanges are some of the designs you're likely to find useful, but it doesn't matter whether they have names, you'll probably reinvent those and also brand new ones yourself.
The first 25 levels are a tutorial for the mechanics, and each will only take a matter of seconds. After that, you'll get the first real problem to solve. Most levels take 10-30 minutes to solve. There's calm music playing in the background, and no time pressure as long as you don't mind cars honking at you if you cause a traffic jam.