Trail_Handbook-Guidelines.doc

2309.18_20

PAGE

WO AMENDMENT 2309.18-2008-4

EFFECTIVE DATE: 10/16/2008

DURATION: This amendment is effective until superseded or removed.

2309.18_20

FSH 2309.18 – trails management handbook

Chapter 20 – trail development

Forest Service Handbook national headquarters (wo)

Washington, DC fsH 2309.18 – TRAILS MANAGEMENT HANDBOOK chapteR 20 – TRAIL development Amendment No.: 2309.18-2008-4 Effective Date: October 16, 2008 Duration: This amendment is effective until superseded or removed.

Approved: charles L. myers

Associate Deputy Chief, NFS Date Approved: 09/30/2008

Posting Instructions: Amendments are numbered consecutively by handbook number and calendar year. Post by document; remove the entire document and replace it with this amendment. Retain this transmittal as the first page(s) of this document. The last amendment to this handbook was 2309.18-2008-3 to 2309.18_10.

New Document

(Amendment 2309.18-91-2, 11/08/1991) 2309.18,2

(Amendment 2309.18-91-2, 11/08/1991)

2309.18,2.31a, Ex. 01

(Amendment 2309.18-91-2, 11/08/1991)

2309.18,2.31b, Ex. 01

(Amendment 2309.18-91-2, 11/08/1991)

2309.18,2.31d, Ex. 01

(Amendment 2309.18-91-2, 11/08/1991)

2309.18,2.32a, Ex. 01

(Amendment 2309.18-91-2, 11/08/1991)

2309.18,2.32b, Ex. 01

(Amendment 2309.18-91-2, 11/08/1991

2309.18,2.32c, Ex. 01

(Amendment 2309.18-91-2, 11/08/1991)

2309.18,2.32d, Ex. 01

(Amendment 2309.18-91-2, 11/08/1991) 2309.18,2.33a, Ex. 01

(Amendment 2309.18-91-2, 11/08/1991) 1 Page

19 Pages

1 Page

2 Pages

1 Page

2 Pages

2 Pages

2 Pages

1 Page

2 Pages

Digest:

Notice of issuance of this directive was published in the Federal Register on October 16, 2008 (73 FR 61600).

Recodes chapter from 1 digit to 2 digits to conform to standard Forest Service directive format.

20.2 – Revises “Objectives” to include Trail Management Objectives (TMOs).

21 - Changes caption from “Sequence of Events” to “Planning, Preparation, and Implementation of Trail Projects,” and enumerates trail project steps in exhibit 01.

22.1 - Changes caption from “Recreation Opportunity Spectrum” to “Trail Management Objectives (TMOs),” and adds reference to FSM 2353.12.

22.2 – Changes caption from “Difficulty Levels” to “Recreation Opportunity Spectrum,” and revises direction previously set forth at 2.21.

22.3 – Changes caption from “Trailheads” to “Trail Class and Level of Challenge,” and adds direction previously set forth at 2.22.

22.4-22.45 – Changes captions, and recodes to this section direction previously set forth at 2.23-2.23e.

22.5 – Establishes new code and caption, “Facilities and Associated Constructed Features Along Trails,” and sets forth new direction.

22.6 – Establishes new code and caption, “Wilderness Considerations,” and clarifies direction.

23 – Changes caption from “Trail Construction and Maintenance Guides” to “Design Parameters.”

23.1 – Changes caption from “Nonmotorized Trails” to “Standard Terra Trails: Non-Motorized.”

23.11-23.13 – Changes captions, and adds exhibits for the Design Parameters for Hiker/Pedestrian, Pack and Saddle, and Bicycle.

23.2 – Changes caption from “Motorized Trails” to “Standard Terra Trails: Motorized.”

23.21-23.23 – Changes captions and adds exhibits for the Motorcycle Design Parameters, All-Terrain Vehicle Design Parameters, and Design Parameters for Four-Wheel Vehicles Greater Than 50 Inches in Width.

Digest--Continued:

23.3 – Changes caption from “Special Trails” to “Snow Trails.”

23.31-23.33 – Changes captions, and adds exhibits for the Cross-Country Ski Design Parameters, Snowshoe Design Parameters, and Snowmobile Design Parameters.

23.4 – Establishes a reserved code and caption, “Water Trails.”

23.5 – Establishes new code and caption, “Special Trails,” and sets forth direction, including “Accessible Trails” at 23.51 and “Interpretive Trails” at 23.52. Recodes to this section direction previously set forth in 2.33a and 2.33b.

Table of Contents

520.2 – Objectives

521 – PLANNING, PREPARATION, AND IMPLEMENTATION OF TRAIL PROJECTS

722 - GENERAL DESIGN CONSIDERATIONS

722.1 - Trail Management Objectives (TMOs)

722.2 - Recreation Opportunity Spectrum

722.3 – Trail Class and Level of Challenge

722.4 - Trailheads

722.41 – Trailhead Location

822.42 – Trailhead Parking

822.43 – Pack and Saddle Trailheads

922.44 – Snow Removal at Trailheads

1022.45 – Application of Forest Service Trail Accessibility Guidelines (FSTAG) at Trailheads

1022.5 – Facilities and Associated Constructed Features Along Trails

1122.6 – Wilderness Considerations

1123 – DESIGN PARAMETERS

1223.1 – Standard Terra Trails – Non-Motorized

1223.11 – Hiker/Pedestrian Design Parameters

1523.12 – Pack and Saddle Design Parameters

1923.13 – Bicycle Design Parameters

2223.2 – Standard Terra Trails - Motorized

2223.21 – Motorcycle Design Parameters

2623.22 - All-Terrain Vehicle (ATV) Design Parameters

3023.23 – Design Parameters for Four-Wheel Drive Vehicles Greater Than 50 Inches in Width

3423.3 – Snow Trails

3423.31 – Cross-Country Ski Design Parameters

3823.32 – Snowshoe Design Parameters

4123.33 – Snowmobile Design Parameters

4523.4 - Water Trails [Reserved]

4523.5 - Special Trails

4523.51 - Accessible Trails

4723.52 - Interpretive Trails

20.2 – Objectives

1. Provide trails that meet their Trail Management Objectives (TMOs), are consistent with the applicable land management plan, provide opportunities for satisfying recreation experiences, harmonize with and provide opportunities for enjoyment of the national forest or grassland setting, and minimize maintenance costs.

2. Design, construct, and maintain sustainable trails, that is, trails that withstand the wear and tear of normal traffic and reasonable user behavior during the managed season of use and that have minimal negative effects on adjacent resources.

21 – PLANNING, PREPARATION, AND IMPLEMENTATION OF TRAIL PROJECTS

The chart on the following page shows the steps that should be followed in planning, preparing, and implementing a trail project.

21 - Exhibit 01

PLANNING, PREPARATION, AND IMPLEMENTATION OF TRAIL PROJECTS

Design Elements Selection

Route Investigation

Placement of Preliminary Flag Lines

Environmental Analysis

Final Route Selection

Commence Right-of-Way Acquisition (if needed)

Placement of Preliminary Flag Lines

Trail Classification Data

Project Cost Estimate

Final Design

Review of Plans

Contract Administration

22 - GENERAL DESIGN CONSIDERATIONS

The following direction applies to the reconnaissance phase of project-level trail planning.

22.1 - Trail Management Objectives (TMOs) Incorporate applicable TMOs in the design and development of each National Forest System (NFS) trail (FSM 2353.12).

22.2 - Recreation Opportunity Spectrum

1. The Recreation Opportunity Spectrum (ROS) identifies experience levels and management prescriptions to provide a diversity of recreation experiences.

2. Trail development and uses must reflect trail direction in the applicable land management plan, including the ROS classes identified in the plan (FSM 2311.1).

22.3 – Trail Class and Level of Challenge

1. Trail Classes generally reflect the level of recreational challenge provided by a trail, including the corresponding level of user skill and experience needed to negotiate the trail. For example, a trail in Trail Class 2 normally is constructed and maintained to a lower standard than a trail in Trail Class 4. Therefore, a trail in Trail Class 2 is usually more challenging and generally requires more user skill and experience than a trail in Trail Class 4 to traverse.

2. The degree of challenge presented by a trail depends on a combination of trail characteristics, including trail grade, alignment, clearing width, tread conditions, gain or loss of elevation, and other criteria outlined in the Design Parameters (sec. 23.1, ex. 01, through 23.3, ex. 01).

22.4 - Trailheads

22.41 – Trailhead Location

1. Where appropriate, situate trailheads so as to allow access to the greatest number and diversity of trails. Depending on the circumstances, the greatest diversity of trails may include trails with the same Managed Use or with multiple Managed Uses, depending on the combination of uses, relative use levels, and potential for use conflicts. Match the development scale and size of the trailhead facility to the carrying capacity of the area and to the Trail Classes of the trails to be served.

2. In locating trailheads, consider snow use as well as non-snow use where appropriate, along with opportunities for using existing facilities. Other pertinent considerations include the ability to provide pull-through parking for vehicles with trailers and space for unloading trailers and stock trucks and safety of unattended vehicles.

3. Use visual resource management principles to minimize the visual impacts of the trailhead on trail users (see FSM 2380 and Landscape Aesthetics: A Handbook for Scenery Management, USDA Agriculture Handbook 701).

4. All constructed features must comply with the applicable technical provisions of the Architectural Barriers Act Accessibility Standards (ABAAS) or the Forest Service Outdoor Recreation Accessibility Guidelines (FSORAG). The routes connecting constructed features at trailheads must comply with the technical provisions for outdoor recreation access routes in the FSORAG. The FSORAG is available electronically at http://www.fs.fed.us/recreation/programs/accessibility.

22.42 – Trailhead Parking

1. When space is available, consider separate parking facilities for certain uses, such as horseback riding and hiking. Provide separate facilities within walking distance of areas of concentrated public use, such as campgrounds. Locate the trailhead next to a trail so that non-highway-legal vehicles are not forced to travel on roads that may be used only by highway-legal vehicles.

2. When 5 or more designated parking spaces are provided at a trailhead, they must comply with the technical provisions in ABAAS for accessible parking spaces.

22.43 – Pack and Saddle Trailheads

1. The trailhead needs of pack and saddle animal users vary with the type of vehicles used for transportation, the number of animals being handled, and the length of stay at the trailhead.

2. Many animals are transported in trailers or trucks equipped with portable ramps. Therefore, unloading ramps are not needed at every trailhead. As an alternative, consider designing an earthen bank for unloading.

3. Trailheads used primarily for day trips require less development than those used for overnight trips.

4. Trailheads with a full range of facilities, such as a loading ramp, a corral, a water source, hitching racks, and feed bunks, may be justified if the objective is to have users bring pack and saddle animals out of the backcountry for the night. Fully developed trailheads may be especially desirable in areas with scarce forage or fragile soils. Provide toilets and fire rings where needed.

5. Corrals are expensive to construct and maintain and should be considered only when animals need to be held for more than one or two nights. Many owners are reluctant to place their animals in a corral with other animals with which they are not familiar.

6. A watering source for livestock is an important consideration. A trail to a nearby stream may suffice, but for heavy-use sites, consider piping in water to a watering tank.

22.44 – Snow Removal at Trailheads Coordinate plowing at trailheads with the local public road authority. If rotary plows will be used, pave the surface of the road or parking lot. The size of the plowed parking area will provide an upper limit for trail use. Consider the following when providing winter parking at trailheads:

1. Snow Removal.

a. Adequate surface for snowplowed lots.

b. Adequate slope for drainage and operation of appropriate equipment.

c. Proximity to buildings and surface obstructions.

2. Size and Shape of Parking Lot.

a. Design that allows for efficient snow removal and use. A compromise between the visual resource and efficiency of snow removal may be necessary.

b. Maneuverability of necessary equipment.

3. Adequate Snow Storage.

a. Sufficient room for snow storage to prevent removal of the same snow multiple times.

b. Protection of adjacent vegetation from mechanical or chemical damage incidental to snow clearing.

4. Access Road.

a. Adequate width.

b. Availability of proper storage for snow removed from the road.

c. Situated at a reasonable distance from major access points.

d. Minimal curvature.

e. Grade of less than 3 percent.

f. Adequate visibility at parking area or access road entrances.

22.45 – Application of Forest Service Trail Accessibility Guidelines (FSTAG) at Trailheads Ensure that all new or altered trails with a Designed Use of Hiker/Pedestrian that connect directly to a trailhead or to a currently accessible trail comply with the FSTAG. The FSTAG is available electronically at http://www.fs.fed.us/recreation/programs/accessibility.

22.5 – Facilities and Associated Constructed Features Along Trails

1. Facilities and associated constructed features along trails include shelters, toilets, and other structures that provide support for trail users. These facilities and associated constructed features must comply with the FSORAG under the Forest Service’s universal design policy.

2. Facilities and associated constructed features along trails must be designed appropriately for the setting and in compliance with the FSORAG to ensure that the facilities can be used for their primary purpose by all hikers, including hikers with disabilities. See the FSORAG for specific technical provisions. This requirement applies but is not limited to:

a. Pit Toilets With No Walls. The total height of the toilet seat and the riser it sits on must be 17 to 19 inches above the ground or floor. A clear floor or ground space complying with section 6.6.6 of the FSORAG must be provided adjacent to the riser. Since walls are not provided, grab bars are not required.

b. Trail Shelters or Lean-Tos With Three Walls. Where the constructed finished floor elevation is above the ground, a shelter or lean-to must be located so that at least one section of the floor on the open side of the shelter or lean-to is 17 to 19 inches above ground to facilitate transfer from a wheelchair.

22.6 – Wilderness Considerations

1. The applicable land management plan establishes specific objectives for wilderness management, including appropriate levels and types of use. Plan and manage the trail system serving a wilderness area in accordance with these objectives (FSM 2323).

2. The criteria for locating, constructing, and maintaining trails in a wilderness area are based on the management objectives outlined in the applicable wilderness plan. At a minimum, locate, construct, and maintain trails in a wilderness area so as to achieve the following goals:

a. To give the appearance of being a part of the wilderness area, rather than an intrusion upon it.

b. To meet and maintain the levels of acceptable use established for specific locations in the wilderness area.

c. To meet the setting requirements for the Recreation Opportunity Spectrum (ROS) class established for specific locations in the wilderness area.

d. To meet the scenic integrity objectives established for specific locations in the wilderness area.

e. To protect the safety of users consistent with the normal degree of difficulty they would likely encounter during the primary season of public use.

f. To protect and perpetuate the wilderness character of the area.

g. To construct and maintain trails with non-motorized equipment.

h. To provide trail treads that do not exceed 24 inches in width.

23 – DESIGN PARAMETERS

Identify Design Parameters for each NFS trail or trail segment based on the guidance in section 14.5 and the corresponding set of Design Parameters in sections 23.1 through 23.3.

The following sets of Design Parameters are included as exhibits in sections 23.1 through 23.3:

1. Section 23.1 – Standard Terra Trails: Non-Motorized.

a. Hiker/Pedestrian.

b. Pack and Saddle.

c. Bicycle.

2. Section 23.2 – Standard Terra Trails: Motorized.

a. Motorcycle.

b. All-Terrain Vehicle (ATV).

c. Four-Wheel Drive Vehicle Greater Than 50 Inches in Width.

3. Section 23.3 – Snow Trails.

a. Cross-Country Ski.

b. Snowshoe.

c. Snowmobile.

4. Section 23.4 – Water Trails [Reserved].

Besides the Designed Uses included in the Design Parameters, there are a variety of other Managed Uses, such as dog sledding. Regional sets of Design Parameters may be developed for these Managed Uses, if needed. If these Managed Uses become common, a national set of Design Parameters may be developed for those uses.

For definitions of the design attributes in each set of Design Parameters (including Design Tread Width, Design Surface, Design Grade, Design Cross Slope, Design Clearing, and Design Turns), refer to section 05.

23.1 – Standard Terra Trails – Non-Motorized

23.11 – Hiker/Pedestrian Design Parameters

The next page displays the Hiker/Pedestrian Design Parameters, followed by considerations regarding their application.

23.11 - Exhibit 01

HIKER/PEDESTRIAN DESIGN PARAMETERS

Design Parameters are technical guidelines for the survey, design, construction, maintenance, and assessment of National Forest System trails, based on their Designed Use and Trail Class and consistent with their management intent1. Local deviations from any Design Parameter may be established based on trail-specific conditions, topography, or other factors, provided that the deviations are consistent with the general intent of the applicable Trail Class.

Designed Use

HIKER/PEDESTRIAN

(Single Lane)

Exception: may be

36” – 48” at steep side slopes 18” – 24”

Exception: may be 36” – 48” at steep side slopes Not applicable

Non-Wilderness

(Single Lane)

24” – 60”

36” – 72”

Non-Wilderness

(Double Lane)

Structures

(Minimum Width)

May be continuously rough

Native, limited grading

Native, with some on-site borrow or imported material where needed for stabilization and occasional grading Intermittently rough Native with improved sections of borrow or imported material, and routine grading Minor roughness

Likely imported material, and routine grading Uniform, firm, and stable

Likely common and continuous ≤ 6”

May be common and continuous ≤ 3”

May be common, not continuous ≤ 3 ”

Uncommon, not continuous No protrusions

Obstacles

(Maximum Height) 24”

14”

10”

8”

No obstacles

23.11 – Exhibit 01--Continued Designed Use

HIKER/PEDESTRIAN

Short Pitch Maximum

FSTAG: 5% – 12%2

20% – 30% of trail

10% – 20% of trail

5% – 20% of trail

0% – 5% of trail

(or crowned)

Some vegetation may encroach into clearing area 24” – 48”

Some light vegetation may encroach into clearing area 36” – 60”

48” – 72”

60” – 72”

1 For definitions of Design Parameter attributes (e.g., Design Tread Width and Short Pitch Maximum), see FSH 2309.18, section 05.

2 Trail Classes 3, 4, and 5, in particular, have the potential to be accessible. If assessing or designing trails for accessibility, refer to the Forest Service Trail Accessibility Guidelines (FSTAG) for more specific technical provisions and tolerances (FSM 2350).

3 The determination of the trail-specific Design Grade, Design Surface, and other Design Parameters should be based upon soils, hydrological conditions, use levels, erosion potential, and other factors contributing to surface stability and overall sustainability of the trail.

Application considerations for Hiker/Pedestrian Design Parameters:

1. Trails with a Designed Use of Hiker/Pedestrian generally require less development than trails with another Designed Use, thereby offering the greatest opportunity to bring users close to nature. Tread width, clearing width and height, alignment, and structures for crossing streams normally are at a smaller scale.

2. On trails with a Designed Use of Hiker/Pedestrian, grades leading to and from switchbacks should not be less than 10 percent. Within the turn, reduce the grade to less than 10 percent for a distance of 5 or 6 feet. When needed, reduce or eliminate creation of switchbacks by trail users by installing rocks, logs, native vegetation, or other material.

3. When trails with a Designed Use of Hiker/Pedestrian cross wet areas or streams, select routes that require the fewest structures. When designing structures to cross wet areas, follow the guidance in the Design Parameters regarding the minimum tread width for trail structures. Stepping stones generally should be at least 12 to 18 inches wide, depending on the Trail Class of the trail and its management intent, and should be set no more than 24 inches apart.

4. Design bridges on trails with a Designed Use of Hiker/Pedestrian to prevent overloading, especially if they are located in areas used by pack and saddle stock.

5. The maximum grade for trails in Trail Class 1 with a Designed Use of Hiker/Pedestrian matches the grade for trails in the lowest class of mountaineering routes. However, mountaineering routes, which require the use of unconstructed hand and toe holes or ropes, are not covered by the Hiker/Pedestrian Design Parameters.

23.12 – Pack and Saddle Design Parameters The next page displays the Pack and Saddle Design Parameters, followed by considerations regarding their application.

23.12 - Exhibit 01

PACK AND SADDLE DESIGN PARAMETERS

Design Parameters are technical guidelines for the survey, design, construction, maintenance, and assessment of National Forest System trails, based on their Designed Use and Trail Class and consistent with their management intent1. Local deviations from any Design Parameter may be established based on trail-specific conditions, topography, or other factors, provided that the deviations are consistent with the general intent of the applicable Trail Class.

Designed Use

PACK AND SADDLE

(Single Lane)

May be up to 48” along steep side slopes

48” – 60” or greater along precipices 18” – 24”

May be up to 48” along steep side slopes

48” – 60” or greater along precipices 24”

May be up to 48” along steep side slopes

48” – 60” or greater along precipices Typically not designed or actively managed for equestrians, although use may be allowed

Non-Wilderness

(Single Lane)

12” – 24”

May be up to 48” along steep side slopes

48” – 60” or greater along precipices 18” – 48”

48” – 60” or greater along precipices 24” – 96”

48” – 60” or greater along precipices

Non-Wilderness

(Double Lane)

Structures

Other than bridges: 36”

Bridges without handrails: 60”

Bridges with handrails: 84” clear width Other than bridges: 36”

Bridges without handrails: 60”

Bridges with handrails: 84” clear width Other than bridges: 36”

Bridges without handrails: 60”

Bridges with handrails: 84” clear width

Native, with limited grading May be frequently rough Native, with some on-site borrow or imported material where needed for stabilization and occasional grading Intermittently rough Native, with improved sections of borrow or imported material and routine grading

23.12 – Exhibit 01--Continued

Designed Use

PACK AND SADDLE

Design Surface (continued) Protrusions

≤ 6”

May be common and continuous ≤ 3”

May be common, not continuous ≤ 3”

Uncommon, not continuous

Obstacles

12”

5% – 20%

Short Pitch Maximum

Maximum Pitch Density

15% – 20% of trail

5% – 10%

Maximum Cross Slope

10%

8’ – 10’

10’

10’ – 12’

Width

72”

72” – 96”

96”

Shoulder Clearance

6” – 12”

Pack clearance: 36” x 36” 12” – 18”

Pack clearance: 36” x 36” 12” – 18”

Pack clearance: 36” x 36”

4’ – 5’

1 For definitions of Design Parameter attributes (e.g., Design Tread Width and Short Pitch Maximum), see FSH 2309.18, section 05.

2 The determination of the trail-specific Design Grade, Design Surface, and other Design Parameters should be based upon soils, hydrological conditions, use levels, erosion potential, and other factors contributing to surface stability and overall sustainability of the trail.

Application considerations for Pack and Saddle Design Parameters:

1. Trails with a Designed Use of Pack and Saddle are designed and maintained to accommodate a wide variety of pack and saddle animals, including horses, mules, donkeys, and burros. Some of these trails are simple day-use bridle paths, and others are built to accommodate long strings of pack animals on journeys lasting many days. The combination of shorter and longer trails affords opportunities for natural experiences with the greatest range in user ability and knowledge.

2. When locating trails with a Designed Use of Pack and Saddle, give special consideration to the care and safety of livestock and riders. If practical, provide reasonable access to streams or lakes for stock watering at intervals of no more than 10 miles. To the extent practicable, notify equestrians if intervals between water sources are excessive. Avoid locations near campgrounds or other areas of concentrated use, where dogs or loud noises could startle pack and saddle animals. If the trail must cross highways or railroads, select sites with adequate visibility at the crossing point.

3. Consider the use of climbing turns if the terrain permits, incorporating a curve radius of 4 feet or greater, depending on the Trail Class and site-specific conditions. Design switchbacks with a curve radius as long as possible and a radius of 5 feet or greater, depending on the Trail Class and site-specific conditions. To discourage shortcutting between switchbacks by trail users, design grades of at least 10 to 15 percent for a distance of 100 feet leading to and from switchbacks. Consider using a rock or log barrier for a distance of 15 to 30 feet from the turning point.

4. Clearing needs for trails with a Designed Use of Pack and Saddle may vary depending on whether the trails are designed for day rides or pack animals.

5. Additional widening is needed to accommodate pack clearance on trails cut through solid rock on steep side hills. Along a precipice or other hazardous area, the trail base should be at least 48 to 60 inches wide to be safe for both animals and riders.

6. Pack and saddle animals can cause severe wear and tear on trail tread, especially when soils are wet. When possible, locate trails on stable soil types or on side slopes, where water is drained away. Gravel surfacing, turnpike, or puncheons may be needed on wet sections.

7. Fords are preferred over bridges for stream crossings, provided the velocity and depth of the water are acceptable for fording during the normal season of use. Generally, streams can be forded safely if they are less than 24 inches deep and the current is moderate. Where feasible, route trails to natural fords, rather than building fords.

8. Construction of a ford requires widening the trail base to at least 36 inches, removing large rocks, and flattening the stream bottom to make a relatively smooth and level crossing. If necessary to make the ford viable, widen the streambed to reduce depth and velocity. Ice buildup during late fall may be an important factor to consider in determining whether to construct a ford.

9. If a decision is made to build a bridge for pack and saddle animals, select a site with an adequate foundation for abutments and stream piers. The bridge must have a load-carrying capacity equal to the weight of the maximum number of loaded animals that can occupy the bridge at one time or the maximum anticipated snow load, whichever is greater. Design railings to prevent packs from getting caught. For minimum bridge widths and railing heights, see FSH 7709.56b, section 7.69, exhibit 01, Trail Bridge Design Criteria.

23.13 – Bicycle Design Parameters

The next page displays the Bicycle Design Parameters.

23.13 – Exhibit 01

BICYCLE DESIGN PARAMETERS

Design Parameters are technical guidelines for the survey, design, construction, maintenance, and assessment of National Forest System trails, based on their Designed Use and Trail Class and consistent with their management intent1. Local deviations from any Design Parameter may be established based on trail-specific conditions, topography, or other factors, provided that the deviations are consistent with the general intent of the applicable Trail Class.

Designed Use

BICYCLE

Structures

Sections of soft or unstable tread on grades < 5% may be common and continuous

Native, with limited grading

Sections of soft or unstable tread on grades < 5% may be common

Native, with some on-site borrow or imported material where needed for stabilization and occasional grading

Sections of soft or unstable tread on grades < 5% may be present, but not common Native, with improved sections of borrow or imported materials and routine grading Stable, with minor roughness

Likely imported material and routine grading Uniform, firm, and stable

Likely common and continuous ≤ 6”

May be common and continuous ≤ 3”

May be common, but not continuous ≤ 3”

Uncommon and not continuous No protrusions

Obstacles

24”

23.13 – Exhibit 01--Continued

Designed Use

BICYCLE

Short Pitch Maximum

30%

50% on downhill segments only 25%

35% on downhill segments only

Some vegetation may encroach into clearing area 36” – 48”

60” – 72”

72” – 96”

72” – 96”

3’ – 6’

4’ – 8’

1 For definitions of Design Parameter attributes (e.g., Design Tread Width and Short Pitch Maximum), see FSH 2309.18, section 05.

2 The determination of the trail-specific Design grade, Design Surface, and other Design Parameters should be based upon soils, hydrological conditions, use levels, erosion potential, and other factors contributing to surface stability and overall sustainability of the trail.

Application considerations for Bicycle Design Parameters may be developed as determined necessary.

23.2 – Standard Terra Trails - Motorized

23.21 – Motorcycle Design Parameters

The next page displays the Motorcycle Design Parameters, followed by considerations regarding their application.

23.21 – Exhibit 01

MOTORCYCLE DESIGN PARAMETERS

Design Parameters are technical guidelines for the survey, design, construction, maintenance, and assessment of National Forest System trails, based on their Designed Use and Trail Class and consistent with their management intent1. Local deviations from any Design Parameter may be established based on trail-specific conditions, topography, or other factors, provided that the deviations are consistent with the general intent of the applicable Trail Class.

Designed Use

MOTORCYCLE

Design

Tread Width

Double Lane

48”

Structures

Native, with limited grading

Native, with some on-site borrow or imported material where needed for stabilization and occasional grading

Sections of soft or unstable tread on grades < 5% may be present Native, with imported materials for tread stabilization likely and routine grading

Sections of soft tread not common

Protrusions

≤ 6”

May be common and continuous ≤ 3”

May be common, but not continuous ≤ 3”

Obstacles

18”

May be common or placed for increased challenge 12”

Common and left for increased challenge

3”

Uncommon

23.21 – Exhibit 01--Continued

Designed Use

MOTORCYCLE

Design

Grade 2 Target Grade

10% – 25%

Short Pitch Maximum

Maximum Pitch Density

20% – 40% of trail

Design

Cross Slope Target Cross Slope

5% – 10%

Maximum Cross Slope

15%

6’ – 7’

Width (On steep side hills, increase clearing on uphill side by 6” – 12”)

36” – 48”

48” – 60”

60” - 72”

Shoulder Clearance

6” – 12”

3’ – 4’

1 For definitions of Design Parameter attributes (e.g., Design Tread Width and Short Pitch Maximum), see FSH 2309.18, section 05.

2 The determination of the trail-specific Design Grades, Design Surface, and other Design Parameters should be based upon soils, hydrological conditions, use levels, erosion potential, and other factors contributing to surface stability and overall trail sustainability.

Application considerations for Motorcycle Design Parameters:

1. NFS trails that allow motorcycle use must be designated for that vehicle class pursuant to 36 CFR 212.51 and displayed on a motor vehicle use map (FSM 7703.1).

2. For NFS trails that have been designated for motorcycle use and that have a Designed Use of Motorcycle, apply the Motorcycle Design Parameters and the following guidance.

a. A variety of distances and recreation experiences may be provided by designing cutoffs for less experienced riders within a system of loop trails. An experienced rider can ride approximately 50 miles in an average day. Some riders can cover over 100 miles in a day.

b. Trail alignment should exhibit decreasing randomness between Trail Class 2 and Trail Class 4.

c. Favor drainage dips over water bars.

d. On trails in Trail Class 4, the alignment is generally moderate, with no sharp curves combined with steep grades. Novice riders may be subjected to sharp curves, but generally not in combination with rough surfaces or steep grades (see sec. 23.21, ex. 01).

e. Favor climbing turns over switchbacks, within the applicable Design Parameter grade tolerances, as deemed appropriate, considering the use and direction of travel. Modify the level of challenge of a curve by increasing or decreasing its turning radius.

f. For trails in Trail Class 4, locate turns on level ground or on slopes of less than 6 percent. On trails designed for novice and intermediate riders, consider providing a 4-to-6-foot barrier on the downhill side of a switchback.

g. The speed of a motorcycle entering a turn varies depending on the radius of the turn. A trail designer can slow the speed of a motorcycle entering a turn by decreasing its turning radius. A trail designer may increase the length of a trail in a limited area by increasing the number of turns.

h. Hardening of switchbacks and climbing turns in sensitive soils is recommended. Suggested hardening materials include concrete blocks, soil, and cement.

i. For minimum bridge widths and railing heights, refer to FSH 7709.56b, section 7.69, exhibit 01, Trail Bridge Design Criteria. Bridges should have a straight approach and should not change directions. Special decking may be necessary to accommodate wheeled vehicles.

j. To minimize confusion, consider locating trail junctions so that no more than two trails intersect at one point.

23.22 - All-Terrain Vehicle (ATV) Design Parameters The next page displays the All-Terrain Vehicle (ATV) Design Parameters, followed by considerations regarding their application.

23.22 – Exhibit 01

ALL-TERRAIN VEHICLE DESIGN PARAMETERS

Design Parameters are technical guidelines for the survey, design, construction, maintenance, and assessment of National Forest System trails, based on their Designed Use and Trail Class and consistent with their management intent1. Local deviations from any Design Parameter may be established based on trail-specific conditions, topography, or other factors, provided that the deviations are consistent with the general intent of the applicable Trail Class.

Designed Use

ALL-TERRAIN VEHICLE

Design

Tread Width

Double Lane

96”

Structures

Native, with limited grading

Native, with some on-site borrow or imported material where needed for stabilization and occasional grading

Sections of soft or unstable tread on grades < 5% may be present Native, with imported materials for tread stabilization likely and routine grading

Sections of soft tread uncommon

Protrusions

≤ 6”

May be common and continuous ≤ 3”

May be common, but not continuous ≤ 3”

Obstacles

12”

May be common or placed for increased challenge 6”

May be common and left for increased challenge 3”

23.22 – Exhibit 01--Continued

Designed Use

ALL-TERRAIN VEHICLE

Design

Grade 2 Target Grade

10% – 25%

Short Pitch Maximum

Maximum Pitch Density

20% – 40% of trail

15% – 30% of trail

10% – 20% of trail

Design

Target Cross Slope

5% – 10%

Maximum Cross Slope

15%

6’ – 7’

Width (On steep side hills, increase clearing on uphill side by 6” – 12”)

60”

60” – 72”

72” - 96”

Shoulder Clearance

0” – 6”

1 For definitions of Design Parameter attributes (e.g., Design Tread Width and Short Pitch Maximum), see FSH 2309.18, section 05.

2 The determination of the trail-specific Design Grade, Design Surface, and other Design Parameters should be based upon soils, hydrological conditions, use levels, erosion potential, and other factors contributing to surface stability and overall sustainability of the trail.

Application considerations for All-Terrain Vehicle Design Parameters:

1. NFS trails that allow ATV use must be designated for that vehicle class pursuant to 36 CFR 212.51 and displayed on a motor vehicle use map (FSM 7703.1).

2. For NFS trails designated for ATV use and that have a Designed Use of ATV, apply the ATV Design Parameters and the following guidance.

a. A variety of distances and recreation experiences may be provided by designing cutoffs for less experienced riders within a system of loop trails.

b. Trail alignment should exhibit decreasing randomness between Trail Class 2 and Trail Class 4.

c. Include frequent elevation changes and turns appropriate for each skill level. These design features can be incorporated as appropriate to slow vehicle speeds, increase safety, and provide more riding time per mile (see sec. 23.22, ex. 01).

d. Favor drainage dips over water bars.

e. Favor climbing turns over switchbacks, within the applicable Design Parameter grade tolerances, as deemed appropriate, considering the use and direction of travel. Modify the level of challenge of a curve by increasing or decreasing its turning radius.

f. On trails in Trail Class 4, the alignment generally should be moderate, with no sharp curves combined with steep grades. Novice riders may be subjected to sharp curves, but generally not in combination with rough surfaces or steep grades. If possible, incorporate climbing turns with a wide radius for ascending hills. Use switchbacks on steep slopes only for more challenging trails.

g. Hardening of switchbacks and climbing turns in areas with sensitive soils is recommended. Suggested hardening materials include concrete blocks, soil, and cement.

h. For minimum bridge widths and railing heights, refer to FSH 7709.56b, section 7.69, exhibit 01, Trail Bridge Design Criteria. Bridges should have a straight approach and should not change directions. Special decking may be necessary to accommodate wheeled vehicles.

i. To minimize confusion, consider locating trail junctions so that no more than two trails intersect at one point.

23.23 – Design Parameters for Four-Wheel Drive Vehicles Greater Than 50 Inches in Width The next page displays the Design Parameters for Four-Wheel Drive Vehicles Greater Than 50 Inches in Width, followed by considerations regarding their application.

23.23 – Exhibit 01

DESIGN PARAMETERS FOR FOUR-WHEEL DRIVE VEHICLES

GREATER THAN 50 INCHES IN WIDTH

Design Parameters are technical guidelines for the survey, design, construction, maintenance, and assessment of National Forest System trails, based on their Designed Use and Trail Class and consistent with their management intent1. Local deviations from any Design Parameter may be established based on trail-specific conditions, topography, or other factors, provided that the deviations are consistent with the general intent of the applicable Trail Class.

Designed Use

FOUR-WHEEL DRIVE VEHICLE > 50"

Design

Tread Width

Double Lane

16’

Structures

Native, with limited grading

May be continuously rough Sections of soft or unstable tread on grades < 5% may be common and continuous Native, with some on-site borrow or imported material where needed for stabilization and occasional grading Intermittently rough Sections of soft or unstable tread on grades < 5% may be present Native, with imported materials for tread stabilization likely and routine grading

Sections of soft tread uncommon

Protrusions

≤ 12”

May be common and continuous ≤ 8”

May be common and continuous ≤ 4”

May be common and continuous

Obstacles

36”

May be common or placed for increased challenge 24”

Common and left for increased challenge 12”

23.23 – Exhibit 01--Continued

Designed Use

FOUR WHEEL DRIVE VEHICLE < 50"

Design

Grade2 Target Grade

10% – 21%

Short Pitch Maximum

Maximum Pitch Density

20% – 30% of trail

Design

Target Cross Slope

8% – 15%

Maximum Cross Slope

15%

6’ – 8’

Width

72” – 84”

72” – 96”

96” - 144”

Shoulder Clearance

0” – 6”

1 For definitions of Design Parameter attributes (e.g., Design Tread Width and Short Pitch Maximum), see FSH 2309.18, section 05.

2 The determination of the trail-specific Design Grade, Design Surface, and other Design Parameters should be based upon soils, hydrological conditions, use levels, erosion potential, and other factors contributing to surface stability and overall sustainability of the trail.

Application considerations for Four-Wheel Drive Vehicles > 50” In Width Design Parameters:

1. NFS trails that allow four-wheel drive vehicle use must be designated for that vehicle class pursuant to 36 CFR 212.51 and displayed on a motor vehicle use map (FSM 7703.1).

2. For NFS trails designated for four-wheel drive vehicles over 50 inches in width and that have a Designed Use for that type of vehicle, apply the appropriate Design Parameters and the guidance below, as applicable.

a. The level of challenge provided by a trail increases with the size of the vehicle. For example, a trail that is challenging for a vehicle with a short wheelbase (less than 100 inches) is likely to be even more challenging for a vehicle with a long wheelbase (greater than 100 inches).

b. Trails designed for four-wheel drive vehicles greater than 50 inches in width have varying degrees of horizontal and vertical alignments, with safe tread for an average speed of 2 to 4 miles per hour.

c. A variety of distances and recreation experiences may be provided for less experienced riders by designing cutoffs within a system of loop trails.

d. Favor drainage dips over water bars.

e. Favor climbing turns over switchbacks, within the applicable Design Parameter grade tolerances, as deemed appropriate, considering the use and direction of travel. Modify the level of challenge of a curve by increasing or decreasing its turning radius.

f. Alignment on trails with grades of 4 percent or less should provide 5 lock-to-lock turns (five changes of direction of the steering wheel, from far right to far left) in the first 150 feet of the trail to restrict use of the trail to smaller vehicles. The rest of the trail should have 2 to 5 lock-to-lock turns, depending on vegetation, topography, and planned challenge level (see sec. 23.23, ex. 01).

g. Trails with grades of 4 to 10 percent should have wider turning radii and dips and bumps, as topography allows. Depending on topography, locate 10 percent or more of the trail on a relatively straight alignment, with a maximum side slope of 30 percent.

23.3 – Snow Trails

23.31 – Cross-Country Ski Design Parameters The next page displays the Cross-Country Ski Design Parameters, followed by considerations regarding their application.

23.31 – Exhibit 01

CROSS-COUNTRY SKI DESIGN PARAMETERS

Design Parameters are technical guidelines for the survey, design, construction, maintenance, and assessment of National Forest System trails, based on their Designed Use and Trail Class and consistent with their management intent1. Local deviations from any Design Parameter may be established based on trail-specific conditions, topography, or other factors, provided that the deviations are consistent with the general intent of the applicable Trail Class.

Designed Use

CROSS-COUNTRY SKI

Typically not groomed

6’ – 8’

Or width of grooming equipment 8’– 10”

Typically not designed or actively managed for cross-country skiing, although use may be allowed

Double Lane

6’ – 8’

Structures

Generally no machine grooming

May receive occasional machine grooming for snow compaction and track setting

Regular machine grooming for snow compaction and track setting

Protrusions

No protrusions

Obstacles

12”

8”

(no obstacles if machine groomed) No obstacles

23.31 – Exhibit 01--Continued

Designed Use

CROSS-COUNTRY SKI

5% – 15%

Short Pitch Maximum

Maximum Pitch Density

10% – 20% of trail

Design Cross Slope

Target Cross Slope

0% – 10%

Maximum Cross Slope (For up to 50’)

(Above normal maximum snow level)

6’ – 8’

8’

Or height of grooming equipment 8’ – 10’

Width

24” – 60”

Light vegetation may encroach into clearing area 72” – 20”’

Light vegetation may encroach into clearing area 96”’ – 168”

Widen clearing at turns or if increased sight distance needed

Shoulder Clearance

0” – 6”

8’ – 10’

15’ – 20’

Or to accommodate grooming equipment ≥ 25’

1 For definitions of Design Parameter attributes (e.g., Design Tread Width and Short Pitch Maximum), see FSH 2309.18, section 05.

2 The determination of the trail-specific Design Grade, Design Surface, and other Design Parameters should be based upon soils, hydrological conditions, use levels, erosion potential and other factors contributing to surface stability and overall sustainability of the trail Application considerations for Cross-Country Ski Design Parameters:

1. Trails with a Designed Use of Cross-Country Ski are Snow Trails that are designed and managed for travel during the snow season. They may, however, overlap a Standard Terra Trail that is managed for use when there is no snow. When this overlap occurs, identification of the applicable Design Parameters should be based on consideration of both the Designed Use for the Standard Terra Trail and the Designed Use for the Snow Trail. From the two Designed Uses, select the Design Parameters with the most demanding design, construction, and maintenance requirements (sec. 14.4).

2. Locate or review potential locations for cross-country ski trails during the winter months.

3. Locate cross-country ski trails where reliable snow conditions exist for 2 to 3 months annually. Utilize topography to extend the period of snow cover. Consider the direction the slope faces, prevailing wind direction, shade, and microclimate when locating cross-country ski trails.

4. Avoid avalanche hazards. Consult with those knowledgeable of local avalanche hazards before developing cross-country ski trails.

5. Avoid hazardous stream and lake crossings. Normally, 6 inches of hard blue ice is considered safe for cross-country ski trail crossings.

6. Avoid locating trails under dense canopies, especially in tall, old-growth stands.