National Trail Surfaces Study

Overview

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. In some cases, natural materials may be bonded with synthetic materials to provide durable firm and stable trail surfaces. The original scope of work for this research project involved a longitudinal study that would examine the influence of five key variables: hydrology, climate, soil condition, grade and cross slope on the accessibility of trail surfaces. The project would involve the installation of 5‒7 different test surfaces in various regions of the country with periodic testing and evaluation of those surfaces by local trained operators. Test plots of eleven different surface materials were installed at Bradford Woods in Martinsville Indiana.

A number of contributing circumstances contributed to the need for a change in the scope of work for this project. When the economic down turn occurred beginning in 2008, entities that had agreed to participate as test sites were forced to withdraw. In addition, stabilizer companies that agreed to provide the applications for the different surface materials for the test plots were unable to provide the labor for installation to the proposed test sites. As a result, only the original test plots installed at Bradford Woods were available for longitudinal testing. In consultation with and with agreement of the Access Board in September 2009, NCA modified the objective of the trail surface study. The experimental trail sections already under testing at Bradford Woods would continue to be tested and data were recorded over 51 months. However, instead of installing and testing new trail plots at selected sites around the country, NCA would actively seek out sites that had stabilizer products already applied and currently being used on natural surface pedestrian trails. Repeated requests were made of stabilizer product companies for trail locations, but few responses were received. Most locations identified did not qualify as pedestrian trails under the definition in the Draft Final Accessibility Guidelines for Outdoor Developed Areas issued by the US Access Board in 2009. Therefore, in January 2010, the National Center on Accessibility issued an interim report on the National Trails Surface Study, which included only the data collected at Bradford Woods up until that date.

Modification to the Scope of Work – Electronic Survey

After filing the January 2010 interim report, investigators at the National Center on Accessibility pursued various research designs and methodologies to properly answer several research questions. As a result of discussions with the U.S. Access Board and the National Park Service, the National Center on Accessibility modified the experimental design of the project. In addition to the continuation of the longitudinal surface testing protocol at Bradford Woods, a new research methodology was designed to provide a pilot test of the methodology and a survey instrument to address some of the research questions from the original study.

Research questions that were to be addressed in this survey included:

1. Geographic, demographic, and political information: type of management agency, park location,trail name, age of trail, length and width of trail, traffic on trail, and similar data

2. Surface product information: product name, manufacturer, initial cost of installation

3. Decisions related to trail: vendor access and information pattern, installation contractor, warranties and guarantees

4. Pre-installation specifications: soil type and composition, surrounding ecosystem, slope and grade of surface

5. Sub-base installation: date of installation, aggregate type, aggregate depth, cost of sub-base, manufacturer, contactor or staff completing installation, time duration for installation, cost of labor for installation

6. Product installation: date of installation, surface product, manufacturer, contactor or staff completing installation, time duration for installation, cost of labor for installation

7. Maintenance: reports of initial repair by type and cost, reports of on-going and continuing repair by type and cost, ease of repair, staff/personnel required to perform repairs and maintenance, cost of labor to perform repair, cost of material to perform repair

8. Product issues: quality of instructions from manufacturer and/or vendor, surface characteristics over time (i.e. uneven wear, settling, cracking, buckling, ruts)

Oklahoma State University was contracted to conduct a survey of professionals in parks and recreation who manage trails designed, developed, and maintained with the natural surface materials or applicable bonded synthetic materials. The survey was administered in the fall of 2011 through the summer of 2012.

This report provides the results of the longitudinal study of the firmness and stability of trail surface materials located at Bradford Woods, at Indiana University. It also provides the national survey results of trail managers administered by Oklahoma State University on the types and characteristics of trail surfaces currently being used around the country.