A desire path (formally referred to as desire line in transportation planning, also known as a game trail, social trail, herd path, cow path, goat track, pig trail or bootleg trail) can be a path created as a consequence of erosion caused by human or animal foot-fall or traffic. The path usually represents the shortest or most easily navigated route between an origin and destination. Width and erosion severity can be indicators of how much traffic a path receives. Desire paths emerge as shortcuts where constructed ways take a circuitous route, have gaps, or are non-existent.