Just tell it where from and to! (Well... as long as it's in the continental US ^_^")
Usage is simple! Make sure to download all the files in the repo into the same folder, and then either compile and run the source file (GettingPlaces.cpp) or alternatively fire up the prepackaged executable (GettingPlaces.exe).
Here's a sample of the kind of things you can do. Let's say you are going from Miami to Orlando, a fairly popular route. Here's what GettingPlaces has to say about this:
The visual is cool, but if you are going to be driving this, you better know which roads you are taking!
You can try any place you want! My personal favortie would be this adventure smack-across the US:
You can imagine the driving instructions for this one...