A greenway is usually a shared-use path along a strip of undeveloped land, in an urban or rural area, set aside for recreational use or environmental protection. Greenways are frequently created out of disused railways, canal towpaths, utility company rights of way, or derelict industrial land. Greenways can also be linear parks, and can serve as wildlife corridors. The path's surface may be paved and often serves multiple users: walkers, runners, bicyclists, skaters and hikers. A characteristic of greenways, as defined by the European Greenways Association, is "ease of passage": that is that they have "either low or zero gradient", so that they can be used by all "types of users, including mobility impaired people".

A rail trail is a shared-use path on railway right of way. Rail trails are typically constructed after a railway has been abandoned and the track has been removed but may also share the right of way with active railways, light rail, or streetcars, or with disused track. As shared-use paths, rail trails are primarily for non-motorized traffic including pedestrians, bicycles, horseback riders, skaters, and cross-country skiers, although snowmobiles and ATVs may be allowed. The characteristics of abandoned railways—gentle grades, well-engineered rights of way and structures, and passage through historical areas—lend themselves to rail trails and account for their popularity. Many rail trails are long-distance trails, while some shorter rail trails are known as greenways or linear parks.