Because trails in public ownership often protect or enhance natural features, the trail corridor becomes or remains a greenway. Greenways can perform many beneficial functions. By protecting the vegetation and geography of natural areas, greenways provide habitat for wildlife. A trail corridor can serve as a conduit for animals by allowing them to move between isolated protected areas linked by the greenway. Greenways along rivers or streams can filter excess nutrients from adjacent lands.
Greenways can also act as a source of water and food for wildlife.
The use of trails can also improve the environment by educating users. This can lead to the development of a deeper environmental ethic, promoting environmental stewardship, and promoting the necessity for responsible use. Utility Trails are by definition corridors, and by being in public ownership these corridors are preserved. Many trail corridors may be suitable for other utility uses, presently or in the future. Trails can share these corridors with public utilities such as water lines, sewer lines, electric lines, fiber optics cable, television cable, etc.