The game has a few simple rules, but the rules of building roads themselves are more difficult to understand:

Roads have three levels that they can be built at: Floor, bridge, and overpass. Overlapping roads of the same tier will form an intersection, but overlapping roads of different tiers will create flyovers, with no conflicting traffic.

You only have a limited amount of concrete to complete each level with. Don't run out!

Building with loops, tight turns, or intersections will cause traffic to slow down, hurting efficiency. Consider if building a bridge would help traffic.

Water must be passed over by bridge or overpass, but some obstacles are completely impassable. Find out where you can build your roads!

Clicking on the signs by roads will reveal traffic demands. Build primary routes with a lot of demand first, then move on to lower-demand routes. Flashing arrows show a connection that doesn't exist yet, while solid ones show a possible connection.

Some levels have pictures you can unlock at certain levels of efficiency. Try to get them all!

Happy building!