Desire paths can usually be found as shortcuts where constructed pathways take a circuitous route.
They are manifested on the surface of the earth in certain cases, e.g., as dirt pathways created by people walking through a field, when the original movement by individuals helps clear a path, thereby encouraging more travel. Explorers may tread a path through foliage or grass, leaving a trail "of least resistance" for followers. The lines may be seen along an unpaved road shoulder or some other unpaved natural surface. The paths take on an organically grown appearance by being unbiased toward existing constructed routes. These are almost always the most direct and the shortest routes between two points, and may later be surfaced. Many streets in older cities began as desire paths, which evolved over the decades or centuries into the modern streets of today."
"Claire was photographing desire paths... the imprints of 'foot anarchists', individuals who had trodden their own routes into the landscape, regardless of the intentions of government, planners and engineers. A desire path could be a short cut through waste ground, across the corner of a civic garden or down an embankment. They were expressions of free will, 'paths with a passion', an alternative to the strictures of railings, fences and walls that turned individuals into powerless apathetic automatons. On desire paths you could break out, explore,'feel your way across the landscape'."
(Nick Crane: Two degrees west, Viking 1999)