The air sings with four-letter words. The iPad sits stoic as fingers poke, jab, and prod at its screen. Traffic engineering, it turns out, is a difficult job, even when you're working in a fantasy "city" made up of nothing but one office building and a solitary tree.

This is the world of Freeways, a new release from independent game maker Justin Smith, who owns Captain Games. The objective is simple enough: build a road network that connects a series of highways and buildings. When you've finished, you'll be scored on three metrics: the average speed of cars on your network, how much concrete you used to build it, and how easy it is for drivers to get from one point to another.

You can make roundabouts, standard intersections, even send one road over another. But plan carefully. Too many merges and you slow everything down. Too many interchanges and you waste money on concrete. Too many intersections and you risk gridlock. Or, as the game puts it when everything grinds to a halt, "Jammed!"

Justin Smith/Captain Games

The mercilessly addictive $3 game, available on Windows computers, iPads, and Android devices with large screens, isn't just a brainteaser. It's a pretty good representation of the work done by the pros, and a handy encapsulation of just how complicated modern road networks can be.

“That balance is something we try to take into account every time we can do a design,” says Kevin Heaslip, a civil and environmental engineer with Virginia Tech. He played Freeways as he waited for his daughter to emerge from gymnastics practice, and liked it so much, he plans to use it in one of his engineering college courses.

Getting traffic to flow smoothly is not simple at all. “The engineers doing this, it’s like a work of art for them,” says Smith. Entire design handbooks outline the most efficient ways to get vehicles through entrance and exit ramps, and engineers pore over geometric possibilities. A diverging diamond interchange here? A magic roundabout there? Even in Freeways' simplified form, the possibilities are overwhelming.

Justin Smith/Captain Games

Freeways can also help explain to aesthetically sensitive drivers why those horrifying looking interchange designs exist in places like Atlanta and Los Angeles. “Spaghetti bowls can be great for traffic flow," says Heaslip. "But people say it’s not the prettiest thing to have around."

The good news for people driving in the real world is that professional engineers have access to more sophisticated software, which accounts for complications like multiple lanes, shifting travel patterns, and traffic signals.

Then there's Freeways' subtler message: What do we lose when we build a transportation network around individual cars, vehicles that require endless swirls of concrete that hog space and public funds? "Maybe this isn’t the transportation mode of the future," Smith says. "Maybe we don’t want to encourage massive interchanges." This game won't provide the answers—but it could keep you occupied the next time you're stuck sitting in traffic.