Trail features are longitudinal areas or lines that people traverse on the ground on foot, bicycle, horse, or any means other than by car. They can be paved or unpaved, in a wilderness area, or in the heart of a city. On a GIS map, they are typically depicted as dotted lines in order to distinguish them from paved roads, which are, in turn, usually solid lines. However, a trail map in an undeveloped area such as a national park may show the trails as solid lines since there are no other solid‑lined features to display. (See Figure 6.74 for color suggestions.) Trails are labeled similarly to rivers and streams, with the labels placed above the trail lines and following the trail curves. If roads are also shown on the map, the trail’s label will be differentiated from the road labels by ensuring that the color of the text is different from the color of the road label text (and, in most cases, matching the trail color). Or, if color differentiation is not possible, then a different font can suffice. These trail names are usually found again somewhere in the map’s marginal elements, where they are listed along with details about each trail. Alternatively, numbers are used in lieu of trail names and serve the same function. If numbers are used as labels, then it is prudent to place the number at the beginning node and along the trail feature at sufficient intervals to enable rapid trail identification. Varying shades of black and brown are usually used for trails, with brown being the obvious choice since many trails are indeed brown on the ground. Red and dusty orange, though, are also good choices, especially for maps with many features to differentiate or when the trail needs to be especially highlighted. Trail features are usually accompanied by ancillary features such as trailhead points, parking areas, and campsite points so that the map can be used for navigation. In such maps, photo‑ graphs of the landscape surrounding a trail at key points, like vistas, lend themselves nicely to the layout margins of a trail map. In terms of line thickness, trail maps used for navigation can show trail lines as thick as and as boldly as typical road features or they can differentiate the trails from roads by utilizing a thinner line style to emphasize the smaller width of a trail in relation to roads. These options depend on the intended focus of the map and the amount of real‑world likeness that is needed or wanted. One of the very interesting problems associated with features like trails that are very narrow, long, and not widely dispersed is how to highlight them without throw‑ ing the map’s visual balance off. As a counterpoint to this, roads, which are also very narrow and long features, are usually well dispersed across a map surface, enough so that the visual impact is more consistent across the page. A trail map, though, might consist of only two or three bike trails that pass through a city. The ratio of city to trail area for a case like this is very large. You might want to show the entire city area