In interstate highways in the United States, even-numbered main highways are generally east-west with increasing highway numbers from south to north, and odd-numbered main highways are generally north-south with increasing highway numbers from west to east.
If one decides to fix the map of the United States to a grid of interstate numbers, we produce the map below. Notice distance skews that make the fact that the highway numbering rules are only a rule of thumb obvious: highways are frequently not spaced anywhere near to scale with numerical difference, and highways sometimes move to the ‘wrong’ side of a ‘parallel’ highway, making, in a notable example in Ohio, Columbus move southwest of Cincinnati.
This map is a rework of a map of this character that I produced two and a half years ago. The previous one was drawn with Microsoft Paint; this one was produced in Raphael.js.