Successful sustainable trail design is equal parts engineering, creativity, and psychology.
To be sustainable the trail must adhere to physical constraints to manage water, minimize erosion, get from A to B, stay within the physical confines of the property, etcetera. The trail designer must also be creative enough to design a trail that is attractive and enjoyable, while also managing disparate, and often conflicting, user needs. Further, the designer must understand the psychology of the user; the trail must go where the users want to go, and must draw them in and down the trail with an engaging experience so they want to stay on the trail. The user should want to know what’s around the next bend, or over the next rise; she should not want to cut that corner or short cut the hill. No amount of trail closing, brushing in or barriers will prevent people from going where they want to go, thus the designer has build a trail to be the preferred route. I teach this in all my trail classes. Whether it’s a fifty foot section over a grade dip, or a five mile section of new trail. Make the trail be the place people want to walk, don’t try to force them to stay on the trail.