mapmaking patterns

In many cases, people will decide which route to take based on slope information. In particularly, they’ll want to know both the steepness of the slope and its direction, but they won’t really need to know the same information about the space between the routes, because they won’t be moving across that space. They’re just moving on the routes.

Develop a symbology on route lines that shows both the grade and direction of slope. Don’t make the reader infer slope of the route based on the slope of the surrounding terrain. Hue is not an intuitive symbol for slope and should be avoided. A recent convention on bike maps uses chevrons (arrowheads) on route symbols that act like discrete miniature contour marks and convey both slope direction and magnitude with two derivative variables (shape of chevrons ‘point’ downhill and spacing between chevrons shows magnitude). Alternatively, both magnitude and direction of slope can be represented when line width represents elevation (e.g. Huffman’s Driftless Area Bike Map), but will only be suitable in places with low road densities and relatively little relief.