HIKER.pdf

WO AMENDMENT 2309.18-2016-x EFFECTIVE DATE: mm/dd/2016 DURATION: This amendment is effective until superseded or removed.

2309.18_20

FSH 2309.18 – TRAILS MANAGEMENT HANDBOOK

CHAPTER 20 – TRAIL DEVELOPMENT

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 Trail Class 1 Trail Class 2 Trail Class 3 2 Trail Class 4 2 Trail Class 5 2

Design Tread Width

Wilderness (Single Lane)

0” – 12” 6” – 18” 12” – 24”

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)

0” – 12” 6” – 18” 18” – 36”

24” – 60”

36” – 72”

Non-Wilderness (Double Lane)

36” 36” 36” – 60” 48” – 72” 72” – 120”

Structures (Minimum Width)

18” 18” 18” 36” 36”

Design Surface3

Type Native, ungraded

May be continuously rough

Native, limited grading

May be continuously 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

Minor roughness

Likely imported material, and routine grading

Uniform, firm, and stable

Protrusions ≤ 24”

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

DURATION: This amendment is effective until superseded or removed.

23.11 – Exhibit 01--Continued

Designed Use

HIKER/PEDESTRIAN Trail Class 1 Trail Class 2 Trail Class 3 2 Trail Class 4 2 Trail Class 5 2

Design Grade 3

Target Grade 5% – 25%

5% – 18% 3% – 12% 2% – 10% 2% – 5%

Short Pitch Maximum

40% 35% 25% 15% 5%

FSTAG: 5% – 12%2

Maximum Pitch Density 20% – 40% of trail

20% – 30% of trail

10% – 20% of trail

5% – 20% of trail

0% – 5% of trail

Design Cross Slope

Target Cross Slope Natural side slope

5% – 20% 5% – 10% 3% – 7% 2% – 3% (or crowned)

Maximum Cross Slope Natural side slope

25% 15% 10% 3%

Clearing

Height 6’

6’ – 7’ 7’ – 8’ 8’ – 10’ 8’ – 10’

Width ≥ 24”

Some vegetation may encroach into clearing area

24” – 48”

Some light vegetation may encroach into clearing area

36” – 60”

48” – 72”

60” – 72”

Shoulder Clearance 3” – 6”

6” – 12” 12” – 18” 12” – 18” 12” – 24”

Turn

Radius No minimum 2’ – 3’ 3’ – 6’ 4’ – 8’ 6’ – 8’

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.

DURATION: This amendment is effective until superseded or removed.

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.