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Accessibility Guidebook for Outdoor Recreation and Trails

Applying the Forest Service Trails Accessibility Guidelines (Continued)

Trail Construction Techniques

There is plenty of good information available to help you build a trail, so we won't repeat it here. The Trail Construction and Maintenance Notebook includes practical techniques used to construct and maintain trails. It is written for trail crew workers and is intended to be taken along on work projects. Numerous illustrations help explain the main points. It is available at 2825P or

The report, Wetland Trail Design and Construction, describes materials and techniques used to construct trails in wetlands. It is written primarily for workers who are inexperienced in wetland trail construction, but it may also be helpful for experienced workers. Techniques suitable for wilderness settings and for more developed settings are included as well as lots of drawings to illustrate important points. It is available at 2833 or

Standard Forest Service trail specifications are available at

Using the Conditions for Departure in the FSTAG

The FSTAG is based on the realities of the outdoor environment and recognizes that accessibility is not feasible everywhere because of limitations imposed by the natural terrain, existing vegetation, or other constraints. To ensure that the unique characteristics of the outdoor environment and trail recreation opportunities aren't compromised or fundamentally altered, exceptions and deviations from some technical provisions are permitted where certain circumstances, called conditions for departure, apply.

Section 7.1.1 of the FSTAG identifies four conditions for departure, and each is explained in more detail below. Circumstances under which exceptions can be made based on the conditions for departure differ depending on the setting. Conditions for departure permit deviations from technical provisions only where there is a general exception or an exception detailed in the technical provision sections for a particular trail component. General exceptions and technical provisions for trail components will be explained later.

Conditions for departure are not a blanket exemption from all of the technical provisions for an entire trail! If a condition for departure occurs only on part of the trail or trail component, the technical provision applies everywhere else, and all technical provisions not affected by the condition for departure also apply. For example, if there is a trail between a stream containing endangered aquatic species and a cliff with petroglyphs on it, and you can't get the required trail width without either filling part of the stream or destroying some petroglyphs, an exception allows a narrower trail past the petroglyphs. One of the conditions for departure is "where compliance would cause substantial harm to cultural...or significant natural features." However, the other technical provisions still apply to that stretch of trail and the technical provision for width still applies to all the rest of the trail.

The conditions for departure cover all the important elements of a long-distance trail and the aspects that are considered when locating trail segments, but they shouldn't be used as an excuse or loophole for failing to make trails accessible. Rather, they are to be used when all other design options have been thoroughly explored and a determination has been made that full compliance with the technical provisions would unacceptably alter the nature of the experience the visitor is seeking.

The four conditions for departure permit deviations from specific technical provisions where allowed by an exception. General examples are provided to help explain the intent of the conditions so that designers understand how to apply them according to the site-specific constraints and opportunities of their projects.

  1. Where compliance would cause substantial harm to cultural, historic, religious, or significant natural features or characteristics.

A significant natural feature might be a large boulder or rocky outcrop, a unique tree or vegetation such as a giant sequoia grove (figure 103), or a body of water that is regarded as distinctive or important locally, regionally, or nationally. Significant natural features also could include areas protected under Federal or State laws, such as habitat for threatened or endangered species, designated wetlands that could be threatened or destroyed by full compliance with the technical provisions, or areas where compliance would substantially harm natural habitat or vegetation.

Photo of a trail winding through a grove of large sequoia trees.
Figure 103—This giant sequoia grove is an
example of a significant natural feature.

Significant cultural features include areas such as archeological or other heritage sites, sacred lands, burial grounds and cemeteries, and tribal protected sites. Significant historical features include properties listed or eligible for listing on the National Register of Historic Places or other places of recognized historic value. Significant religious features include tribal sacred sites and other properties held sacred by an organized religion.

If the significant feature would be directly or indirectly altered, destroyed, or otherwise harmed by construction of the trail or trail element when making it accessible, this condition for departure would apply. Consider only the additional impacts of changes needed to provide accessibility. This condition for departure doesn't apply where substantial impact will result from construction of a trail that is not accessible and only a little more impact is due to construction directly related to accessibility.

  1. Where compliance would substantially change the physical or recreation setting or the trail class or designed use of the trail or trail segment or would not be consistent with the applicable forest land and resource management plan.

Public lands provide a wide variety of recreational experiences, from highly developed areas that offer almost all the conveniences of home and plenty of opportunities to relax with family and friends, to wilderness areas that appear unchanged from primeval times and provide opportunities for individuals to experience primitive and challenging conditions. The FSTAG recognizes the value of the full range of recreational opportunities by allowing exceptions where compliance with technical provisions would change the nature of the recreation opportunities or conflict with the resource management plan.

People using primitive trails, for example, experience the outdoor environment in a nearly natural state, with limited or no development. In these settings, people generally desire challenge and risk so they can use their outdoor and survival skills. Use of manufactured building materials or engineered construction techniques to comply with accessibility requirements could destroy the natural or undeveloped nature of the setting and change the visitor's experience. There is no requirement to dynamite obstacles or pave trails so they will be accessible if doing so would unacceptably change the character of the setting and the recreation opportunity.

Consider a trail intended to provide a rugged experience, such as a cross-country training trail with a steep grade or a fitness challenge course with abrupt and severe changes in elevation. If these trails were flattened out or otherwise constructed to comply with the technical provisions for accessible trails, they wouldn't provide the desired challenge for users. Trails that traverse boulders and rock outcroppings are another example. The purpose of these trails is to provide users with the opportunity to climb the rocks. To remove the obstacles along the way or reroute the trail around the rocks would destroy the purpose of the trail. The nature of the setting also may be compromised by actions such as widening a trail for an imported surface or removing ground vegetation from fragile or erosive soils.

  1. Where compliance would require construction methods or materials that are prohibited by Federal, State, or local law, other than State or local law whose sole purpose is to prohibit use by persons with disabilities.

This condition for departure is best illustrated by example. For instance, federally designated wilderness areas prohibit use of mechanized equipment. If accessibility requirements can't be met with handtools, this condition for departure will apply in wilderness areas. This condition for departure also may apply in areas:

Local law has been included in this condition for departure to address situations where conservation easements or development programs have prohibited or restricted construction methods and practices.

On the other hand, under the Americans with Disabilities Act, State and local governments can't enact laws whose sole purpose is to prohibit use by people with disabilities. Therefore, that sort of law can't serve as a basis for deviation from the technical provisions in the FSTAG. For example, a local regulation that arbitrarily limits trail width to a dimension that wouldn't allow wheelchairs or other assistive devices to access a trail is not a justification for deviation from FSTAG requirements under this condition for departure.

  1. Where compliance would be impractical due to terrain or prevailing construction practices.

The phrase "would be impractical" in this condition for departure refers to something that is not reasonable, rather than to something that is technically infeasible. This condition for departure applies when the effort and resources required to comply would be disproportionately high relative to the level of access created.

Illustration showing a gently sloped trail on a hill with three switchbacks.
Figure 104—A 5-percent grade
trail on a steep hill.
Illustration showing a steep trail on a hill with one switchback.
Figure 105—A traditional trail grade
on a steep hill.

Trail construction practices vary greatly, from reliance on volunteer labor with handtools to professional construction using heavy, mechanized equipment. For alterations of existing trails, "prevailing construction practices" means the methods typically used for work on the trail. For new trails, the land manager determines the construction practices to be used on each trail. However, the choice of construction practice is determined primarily by available resources, such as machinery and skilled operators, and environmental conditions, such as soil type and depth, vegetation, and slope.

The intent of this condition for departure is to ensure that compliance with the technical provisions of the FSTAG does not require the use of construction practices that are beyond the skills and resources of the organization building the trail. This condition for departure is not intended to exempt the trail from the technical provisions of the FSTAG simply because a trail builder's favored construction practice includes the use of a large mechanical roller rather than a smaller vibrating plate or "wacker" type compactor. A contractor's or designer's preference for the larger equipment is not a "feasibility" issue.

This condition also may apply where construction methods for particularly difficult terrain or an obstacle require the use of equipment or methods other than that typically used throughout the length of the trail. In an area where small equipment or handtools are normally used to minimize impact on a sensitive adjacent stream, blasting might be required to remove a rock outcropping. Because blasting is outside the range of typical equipment and methods used, this condition for departure would apply.

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