Decision Process

Step 1: Determine applicability of the FSTAG

Is the designed use¹ for a hiker or pedestrian?

• If no, the FSTAG does not apply.
• If yes, is this a new construction or alteration?
  • If no, the FSTAG does not apply.
  • If yes, does the trail connect to a trailhead or accessible trail?
    • If no, the FSTAG does not apply.
    • If yes, proceed to Step 2: Identify the presence of limiting factors.

Step 2: Identify Presence of Limiting Factors

General Exception 1 (7.1.2.1)

Note: Sequence for identifying limiting factors may vary and does not need to occur in the order illustrated here.

1. Trail Grade
   Does the trail grade exceed 20 percent for 12 meters (40 feet) or more?
   • If no, the FSTAG may still apply. Proceed to limiting factor for surface.
   • If yes, document the length of the trail that exceeds 20 percent and the data source. Does a condition for departure exist?
     • If no, the FSTAG may still apply. Proceed to limiting factor for surface.
     • If yes, is the limiting factor more than 152 meters (500 feet) from a trail terminus?
       • If yes, FSTAG applies between the terminus and this limiting factor or prominent feature. Proceed to Step 3: Apply Technical Provisions.
       • If no, is a prominent feature present?
         • If yes, FSTAG applies between the terminus and this limiting factor or prominent feature. Proceed to Step 3: Apply Technical Provisions.
         • If no, FSTAG does not apply. Document the applicable condition for departure.
           
           
2. Surface
   Is the surface NOT firm and stable for 14 meters (45 feet) or more?
   • If no—the surface IS firm and stable—the FSTAG may still apply. Proceed to limiting factor for minimum trail width.
   • If yes—the surface is NOT firm and stable—document the surface firmness and data source. Does a condition for departure exist?
     • If no, the FSTAG may still apply. Proceed to limiting factor for minimum trail width.
     • If yes, is the limiting factor more than 152 meters (500 feet) from a trail terminus?
       • If yes, FSTAG applies between the terminus and this limiting factor or prominent feature. Proceed to Step 3: Apply Technical Provisions.
       • If no, is a prominent feature present?
       • If yes, FSTAG applies between the terminus and this limiting factor or prominent feature. Proceed to Step 3: Apply Technical Provisions.
       • If no, FSTAG does not apply. Document the applicable condition for departure.
         
         
3. Minimum Trail Width
   Is the minimum trail width less than 457 millimeters (18 inches) for 6 meters (20 feet) or more?
   • If no, FSTAG may still apply. Proceed to limiting factor for trail obstacle.
   • If yes, document the minimum trail width and data source. Does a condition for departure exist?
     • If no, FSTAG may still apply. Proceed to limiting factor for trail obstacle.
     • If yes, is the limiting factor more than 152 meters (500 feet) from a trail terminus?
       • If yes, FSTAG applies between the terminus and this limiting factor or prominent feature. Proceed to Step 3: Apply Technical Provisions.
       • If no, is a prominent feature present?
         • If yes, FSTAG applies between the terminus and this limiting factor or prominent feature. Proceed to Step 3: Apply Technical Provisions.
         • If no, FSTAG does not apply. Document the applicable condition for departure.
           
           
4. Trail Obstacle
   Is a trail obstacle 762 millimeters (30 inches) or higher across the width of the trail?
   • If no, FSTAG may still apply. Proceed to Step 3: Apply Technical Provisions.
   • If yes, document the obstacle type, dimensions, and data source. Does a condition for departure exist?
     • If no, FSTAG may still apply. Proceed to Step 3: Apply Technical Provisions.
     • If yes, is the limiting factor more than 152 meters (500 feet) from a trail terminus?
       • If yes, FSTAG applies between the terminus and this limiting factor or prominent feature. Proceed to Step 3: Apply Technical Provisions.
       • If no, is a prominent feature present?
         • If yes, FSTAG applies between the terminus and this limiting factor or prominent feature. Proceed to Step 3: Apply Technical Provisions.
         • If no, FSTAG does not apply. Document the applicable condition for departure.

Step 3: Apply Technical Provisions

Technical Provisions (7.3.1 to 7.3.8)

1. Trail Grade
   Does the trail grade comply with 7.3.1.1?
• If yes, comply with trail grade technical provision 7.3.1.1.
• If no, does a condition for departure exist?
  • If yes, deviation is permitted. Measure and record the length of the deviation. Proceed to Step 4: Calculate the cumulative deviation percentage.
  • If no, deviation is not permitted. Comply with trail grade technical provision 7.3.1.1.
    
    
2. Trail Cross Slope
   Does the trail cross slope comply with 7.3.1.2?
   • If yes, comply with trail cross slope technical provision 7.3.1.2.
   • If no, does a condition for departure exist?
     • If yes, deviation is permitted.² Measure and record the length of the deviation. Proceed to Step 4: Calculate the cumulative deviation percentage.
     • If no, deviation is not permitted. Comply with trail cross slope technical provision 7.3.1.2.
       
       
3. Resting Interval
   Do resting intervals comply with 7.3.2?
   • If yes, comply with resting interval technical provision 7.3.2.
   • If no, does a condition for departure exist?
     • If yes, deviation is permitted.² Measure and record the length of the deviation. Proceed to Step 4: Calculate the cumulative deviation percentage.
     • If no, deviation is not permitted. Comply with resting interval technical provision 7.3.2.
       
       
4. Surface
   Does the surface comply with 7.3.3?
   • If yes, comply with surface technical provision 7.3.3.
   • If no, does a condition for departure exist?
     • If yes, deviation is permitted.² Measure and record the length of the deviation. Proceed to Step 4: Calculate the cumulative deviation percentage.
     • If no, deviation is not permitted. Comply with surface technical provision 7.3.3.
       
       
5. Clear Tread Width
   Does the clear tread width comply with 7.3.4?
   • If yes, comply with clear tread width technical provision 7.3.4.
   • If no, does a condition for departure exist?
     • If yes, deviation is permitted.² Measure and record the length of the deviation. Proceed to Step 4: Calculate the cumulative deviation percentage.
     • If no, deviation is not permitted. Comply with trail cross slope technical provision 7.3.1.2.
       
       
6. Passing Space
   Do passing spaces comply with 7.3.5?
   • If yes, comply with passing space technical provision 7.3.5.
   • If no, does a condition for departure exist?
     • If yes, deviation is permitted.² Measure and record the length of the deviation. Proceed to Step 4: Calculate the cumulative deviation percentage.
     • If no, deviation is not permitted. Comply with passing space technical provision 7.3.5.
       
       
7. Tread Obstacles
   Do tread obstacles comply with 7.3.6?
   • If yes, comply with tread obstacle technical provision 7.3.6.
   • If no, does a condition for departure exist?
     • If yes, deviation is permitted.² Measure and record the length of the deviation. Proceed to Step 4: Calculate the cumulative deviation percentage.
     • If no, deviation is not permitted. Comply with tread obstacle technical provision 7.3.6.
       
       
8. Protruding Objects
   Do protruding objects comply with 7.3.7?
   • If yes, comply with protruding objects technical provision 7.3.7.
   • If no, does a condition for departure exist?
     • If yes,deviation is permitted.² Measure and record the length of the deviation. Proceed to Step 4: Calculate the cumulative deviation percentage.
     • If no, deviation is not permitted. Comply with protruding objects technical provision 7.3.7.
       
       
9. Openings
   Do openings comply with 7.3.8?
   • If yes, comply with trail grade technical provision 7.3.8.
   • If no, does a condition for departure exist?
     • If yes, deviation is permitted.² Measure and record the length of the deviation. Proceed to Step 4: Calculate the cumulative deviation percentage.
     • If no, deviation is not permitted. Comply with trail grade technical provision 7.3.8.

Step 4: Calculate Cumulative Deviation Percentage

General Exception 2 (7.1.2.2)

1. Cumulative Deviation Percentage
   Do permitted deviations occur on less than 15 percent of total trail length?
   • If yes, apply FSTAG technical provisions to the entire trail.³
   • If no—deviations occur on more than 15 percent—is the first deviation more than 152 meters (500 feet) from a trail terminus?
     • If yes, apply FSTAG technical provisions to the segment of trail between a terminus and the first point of deviation.³
     • If no, is a prominent feature present?
       • If yes, apply FSTAG technical provisions to the segment of trail between a terminus and the prominent feature.³
       • If no, FSTAG does not apply. Document the cumulative deviation percentage.

¹Excerpt from Forest Service Trail Fundamentals (http://fsweb.wo.fs.fed.us/rhwr/ibsc/tr-standards.shtml)
Definition of Designed Use: "The intended use that controls the desired geometric design of the trail, and determines the subsequent maintenance parameters for the trail…. Of the actively Managed Uses that the trail is developed and managed for, the Designed Use is the single design driver that determines the technical specifications for the trail."

Excerpt from Access Board Recommendations for Accessibility Guidelines: Outdoor Developed Areas, Final Report (page 11):
" The accessibility guidelines for trails apply to those which are designed and constructed for pedestrian use. These guidelines are not applicable to trails primarily designed and constructed for recreational use by equestrians, mountain bicyclists, snowmobile users, or off-highway vehicle users, even if pedestrians may occasionally use the same trails. People use these categories of trails by means of transportation other than foot travel or personal mobility device. Design and constructed requirements for equestrians, mountain bikes, OHVs, and snowmobiles are based on the specific requirements for the intended mode of transportation. For the safety of trail users, pedestrian use may not always be permitted on these trails in order to minimize conflicts between motorized and non-motorized recreation. These trails do not preclude use by a person with a disability since it is planned that all trail users would be using the one or more alternative means of transportation for which the trail is designed and constructed. The design and construction of pedestrian trails without consideration of these proposed guidelines, by contrast, could present barriers to some trail users because the intended use is by foot or personal mobility device. For these reasons, the committee intentionally limited the application of the proposed guidelines to pedestrian use trails."

²If at any point during Step 3 the occurrence of one or more conditions of departure result in permitted deviations from technical provisions on more than 15 percent of the trail length, proceed to Step 4.

³Refer to the FSTAG for detailed instructions, definitions, and technical provisions 7.0 through 7.3.