National Trail Surfaces Study

In 2007 the National Center on Accessibility (NCA) entered into an agreement with the U.S. Access Board and National Park Service to investigate natural firm and stable surface alternatives when creating accessible pedestrian trails, including crushed stones, packed soil, and other natural material.

by US Access Board, National Center on Accessibility

February 01, 2014


Trails provide opportunities for people to connect with the natural environment in a variety of settings and are places for all individuals, including people with disabilities. Individuals with disabilities have the same desire to explore nature and physical barriers such as inaccessible surfaces and routes can hamper or even prevent opportunities to participate in the outdoor leisure experience for people with a disability. The purpose of the longitudinal surface study was to evaluate a variety of trail surface materials, and their ability to meet proposed accessibility requirements of firmness and stability from initial installation and maintenance over 51 months.

The research questions included:

  • Does each of the 11 trail surface materials meet or exceed the classifications for firmness and stability as proposed by the US Access Board in their 2007 Notice of Proposed Rulemaking for Outdoor Developed Areas?
  • When evaluating the firmness and stability of each of the 11 trail surface materials, how does each of the 11 trail surface materials compare to themselves over a 51 month time period?
  • When evaluating the firmness and stability of each of the 11 trail surface materials, how does each surface compare to each of the other surfaces over a 51 month time period?

Results from the longitudinal study of trail surfaces included 11 different surface materials installed at Bradford Woods a unit of Indiana University and located in Martinsville, IN. All surface materials displayed varying issue(s) over time that may influence the materials performance and therefore the need for possible frequent maintenance. The implications of quantitative and qualitative data are that a trail composed of an all‐aggregate material, when constructed to specified parameters, could be maintained with little to no maintenance as a firm and stable surface.

In addition to the longitudinal surface study, an electronic survey was conducted of trail managers throughout the United States. The purpose of the trails surface survey was to provide qualified professionals, resource specialists and operations staff of parks and other recreational properties with trails in the United States with descriptive and/or comparative information about the status of construction practices of pedestrian/hiker, natural surface trails in the United States. Despite a sixty‐one percent survey access rate of survey invitees, the overall completion rate was extremely low. Therefore, the results can be addressed in terms of a general trend in types of surface materials used. The majority of trail surfaces were natural materials that did not use soil stabilizers. However, information on construction practices and maintenance issues was limited in the responses received.