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Trail Design for Small Properties provides simple, inexpensive solutions for designing, building, and maintaining sustainable trials—trails for hiking, horseback riding, bicycling, cross-country skiing, snowmobiling, off-highway motorcycles (OHMs), and all-terrain vehicles (ATVs).
If designed with sustainability in mind, a recreational trail can provide years of enjoyment. Sustainable trails require minimal maintenance because their design and materials hold up to intensive recreational use and severe weather conditions.
What kind of tread material is best for your trail? Do you need a bridge to cross open water or will stepping stones do? What tools do you need? We answer these questions and more, providing the information you need to make the right choices for your trail.
The first step in trail design is to determine how the trail will be used, how much it will be used, and what quality of user experience you want to offer.
Multi-use trails work if:
Consider a single-use trail if:
How much will the trail be used at any one time, day, season or year? As trail use increases:
Design your trail to fit the user experience that you want to offer. Consider:
Perhaps the most enjoyable step in trail design is exploring the corridor to determine where to place the trail. A trail corridor is a wide swath through the landscape that encompasses the trail. Analyze the entire area, refining the trail location as you gather more information.
Aerial photographs help you identify land uses on your property and neighboring properties (e.g., cropland, pasture, forest, river, lake), roads, trails, buildings, and utility rightsof- way (fig. 1). Look for photos in a scale of at least 4" to 1 mile, but preferably 8" to 1 mile. Photos are often available from the state department of natural resources, especially the state forestry agency; U.S. Department of Agriculture, Farm Service Agency; U.S. Geological Survey; and Web sites.
Topographic maps (1:24,000 scale) are helpful in hilly and mountainous terrain, especially if your trail covers a large geographic area (fig. 2). They show elevation changes, forest and open areas, rivers, lakes, wetlands, buildings, roads, trails, cemeteries, and other features. Topographic maps may be available from the U.S. Geological Survey, commercial CDs and DVDs, map dealers, and recreational outfitters.
Soil maps and accompanying data tables describe the suitability of soil types for roads, structures, farming, forestry, etc. (fig. 3). Soil maps may be available from your local soil and water conservation district, USDA Natural Resources Conservation Service, county Extension office, or Web sites.
When evaluating large sites, other maps or geographic information systems may provide information on water resources, rights-of-way, utilities, land uses, roads, land ownership, vegetation cover types, wildlife habitat, flood zones, etc. Possible sources include state or national natural resources agencies, local planning and zoning authority, and universities.
Figure 1. An aerial photograph helps identify land uses.
Figure 2. A topographic map shows elevation. The more closely spaced the lines, the steeper the slope.
Figure 3. Match numbers on a soil map to written descriptions of soil capability and limitations.
Scout the corridor in the trail’s primary season of use. To clearly see landscape details, scout when deciduous trees have lost their leaves. If possible, scout in all seasons to reveal attractive features and hazards that may affect location, construction, or maintenance. Look for:
Note existing trails and roads, control points, obstacles, points of interest, and anchor points (fig. 4). Take notes and mark locations on a map or record GIS coordinates.
Figure 4. Consider existing roads and trails, control points, obstacles, points of interest, and anchor points in trail layout.
Figure 5. Trail configuration is the overall shape of a trail.
After exploring the trail corridor, but before flagging the exact trail location, set your design standards. Base the standards on the trail uses; the quality of experience you want to offer, including the level of risk; and your construction resources, including budget and expertise. Use the Recommended Trail Design Standards on pages 6 and 7 as a starting point. Modify them to fit your needs.
Consider these aspects of the trail design: trail configuration, trail length, tread surface, tread width, clearing width, clearing height, grade, turning radius, sight distance, water crossings, and special requirements.
Trail configuration is the overall shape of the trail.
Trail length is the distance that users could travel in one day.
Tread surface refers to the type of surface material (e.g., soil, gravel, rock) and its condition (e.g., smooth, rolling, rough). High-use trails require more durable materials and smoother surfaces than light-use trails.
Figure 6. Tread width, clearing width, and clearing height.
Tread width is the width of the useable trail surface. In general, the tread width that is suitable for light-use or one-way travel should be doubled for heavy-use or two-way travel.
Clearing width is the total width to which rocks, trees, tree limbs, and other obstacles should be removed. As a general rule, clear at least 2' on each side of the tread. Where a trail passes through dense vegetation, vary the clearing width to avoid an unnatural tunnel effect. In general maintain clearing width from the ground up to the clearing height, except you may leave vegetation, rocks, and other objects less than 2´ tall near the tread edge. Center the tread within the clearing width, except on hillside trails where clearance may be less on the downhill side.
Clearing height is the height above the tread surface to which overhanging rocks, tree limbs, and other obstructions must be removed. As a general rule, clear 2´ above the user’s head. Keep in mind that leaves will bend deciduous tree branches 1–2' lower in summer than in winter and snow will bend evergreen tree branches and raise the tread surface.
Figure 7. How to use a clinometer.
Make a clinometer with a protractor, short string, and small weight.
To measure grade:
To convert degrees of slope to percent slope:
Figure 8. Design options for safer turns, especially on steep slopes.
Grade is the slope angle (expressed in degrees or percent) along the trail’s centerline.
% grade = (degrees of angle) x (tangent)
It is easy for trail users to travel long distances on low grades. High grades require more work and should extend for shorter distances. Measure grade with a commercial or homemade clinometer (fig. 7).
Turning radius is the radius of an arc drawn through the centerline of the tread where the trail curves. As travel speed increases, lengthen the turning radius, bank the trail higher on the outside edge, widen the trail, or clear a runout zone (fig. 8).
Sight distance is the distance that a user can see down the trail from any point on the trail. Adhere to the recommended minimum sight distance, but vary sight distances to add interest. Lengthen sight distance to allow faster travel and reduce sight distance to slow travel.
Water crossings refer to the type of structures recommended for crossing bodies of water. A ford, stepping stones, culvert, boardwalk, or bridge may be appropriate. Your choices will be affected by the type of user, type of experience you want to offer, type of water body, length of crossing, legal status of the water body, your ingenuity, and your budget.
Mel Baughman is Associate Dean and Extension Forester in the College of Food, Agricultural and Natural Resource Sciences at the University of Minnesota.
Terry Serres is a graduate student in Natural Resources Science and Management at the University of Minnesota.
Editor/Design: Julie Roles
Illustration: John Molstad
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