FNR-121
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forestry & natural resources
OUTDOOR RECREATION 
Pathways for People
Trail Design to Minimize Environmental Damage and Enhance User Enjoyment
Wendy Hultsman, Asst. Professor of Forestry, and John Hultsman, Asst. Professor of Recreation and Parks
Trails can add considerably to the enjoyment people experience in outdoor recreation areas. Developed for a variety of activities, including hiking, biking, horseback riding, cross-country skiing, snowmobiling, interpretation and off-road vehicle riding, trails can be used to challenge, to teach or simply to provide recreation for a broad spectrum of users. For trails to encourage these activities and achieve these purposes, however, requires advance planning and careful design.
Individuals who design and plan trails have a dual responsibility. They must design for both environmental protection and use. Trails must be easy for resource managers to protect and maintain and, at the same time, be easy for people to use and enjoy.
There are a number of information sources available which deal with trail construction and upkeep, covering such diverse topics as surfacing materials, trail standards, signing methods and periodic maintenance (see “References”). However, there are two other, equally important considerations often ignored during trail development: trail design to minimize damage and to enhance enjoyment.
Designing to Minimize Damage
Trails are a valuable recreational resource which must be protected, and the most critical time to consider their protection or maintenance is during the planning and building phases, when problems can be prevented. If a trail is inadequately designed with respect to maintenance, it will not only require costly upkeep but will also provide a poor experience for users. The most prevalent forms of damage and therefore the ones to be most aware of during the design phase are damage caused by water and damage caused by vandalism.
Minimizing Water Damage
Level Terrain. When trails are located on primarily level terrain, water tends to pool on the trail tread. Building the trail surface slightly above grade allows water to move off the trail. Although this
technique does increase initial construction costs, it decreases later maintenance expenses required to cope with pooled water and also provides a more convenient pathway for users during wet periods. A less expensive technique involves center crowning the trail so water moves to the sides rather than pooling on the trail surface (Figure 1). With either of these techniques, drainage escape channels, or “gutters,” along the edges of the trail should be provided for runoff water.
Figure 1. Center crowning of the trail surface allows water to move to the sides of the trail.
Hilly Terrain. Erosion caused by water movement is a major concern when trails are built in hilly terrain. Most such damage is caused by design and construction errors which allow water to build up volume and velocity. The key to reducing erosion created by water is to move the water off the trail surface as quickly as possible. One method to accomplish this is to outslope, that is, to build the uphill edge of the trail at a slightly higher elevation (2-3%) than the downhill edge (Figure 2). This encourages water to flow perpendicular to, rather than along, the trail surface, thus directing the flow off the trail before erosion can occur.
One of the most common methods for redirecting the downhill flow of water over trail surfaces is through the installation of water bars (Figure 3). This
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