Assuming you're not in a polar region, you should be able to set up a network of NW/SE, and NE/SW roads that never face directly towards the sun; using these, you can get anywhere. As you get farther from the equator, however, the NW/SE and NE/SW roads have to get ever closer to being due N/S roads, so travelling E or W becomes ever more inconvenient. And once you reach an (Ant)-Arctic Circle, no directions are safe.