Desire path
A desire path (often referred to as a desire line in transportation planning, and also known as a game trail, social trail, fishermen trail, herd path, cow path, elephant path, goat track, pig trail, use trail, and bootleg trail) is a path created as a consequence of erosion caused by human or animal traffic. The path usually represents the shortest or most easily navigated route between an origin and destination. The width and severity of erosion are often indicators of the traffic level that a path receives. Desire paths emerge as shortcuts where constructed paths take a circuitous  route, have gaps, or are non-existent. Parks and nature areas. Desire paths sometimes cut through sensitive habitats and exclusion zones, threatening wildlife and park security. However, they also provide park management with an indicator of activity concentration. In Yosemite National Park, the National Park Service uses these indicators to help guide its management plan. Trampling studies have consistently documented that impacts on soil and vegetation occur rapidly with initial use of desire paths. As few as 15 passages over a site can be enough to create a distinct trail, the existence of which then attracts further use. This finding  contributed to the creation of the Leave No Trace education program, which instructs travelers in nature areas to either stay on designated trails or, when off trail, distribute their travel lines so as to not inadvertently create new trails in unsustainable locations. Land managers have devised a variety of techniques to block the creation of desire paths, including fences, dense vegetation, and signage, though none are foolproof. Modern trail design attempts to avoid the need for barriers and restrictions, by aligning trail layout and user desire through physical design and persuasive outreach. Accommodation. Landscapers sometimes accommodate desire paths by paving  them, thereby integrating them into the official path network rather than blocking them. Sometimes, land planners have deliberately left land fully or partially unpathed, waiting to see what desire paths are created, and then paving those. In Finland, planners are known to visit parks immediately after the first snowfall, when the existing paths are not visible. The naturally chosen desire paths, marked by footprints, can then be used to guide the routing of new purpose-built paths. Other uses of the concept. Images of desire paths have been employed as a metaphor for anarchism, intuitive design, individual creativity, and the  wisdom of crowds. In urban planning, desire paths have been used to analyze traffic patterns for a given mode of travel. For example, the 1959 Chicago Area Transportation Study used desire paths to illustrate commuter choices regarding railroad and subway trips. In software design, the term is used to describe users' wide adoption of the same methods to overcome limitations in the software. For example, Twitter has "paved" a number of desire paths by integrating them into the service, including @ replies, hashtags, and group discussions.