QUESTION: I hear there’s a new report about a ground surface study related to trails. Has this happened? If so, can you let me know how to retrieve it? —Dominic, South Dakota

  • Most trail segments tested were treated with a stabilizer.

    Credit: The National Center on Accessibility

    Most trail segments tested were treated with a stabilizer.
ANSWER: Yes, it is ready and available! “National Trail Surfaces Study: Final Report” is the best just-published source I can think of about this topic. The study, which was sponsored by the U.S. Access Board, was completed by the National Center on Accessibility at Indiana University, Bloomington. You can download it here.

The study took place in Indiana, where researchers assessed the firmness and stability of 11 different types of natural aggregate and treated soil surfaces over a four-year period to determine their effectiveness after exposure to the elements, freeze-and-thaw cycles, and other factors. Most trail segments tested were treated with a stabilizer.

Findings indicate that several types of surface materials, when installed according to the study's protocols, maintained a consistently firm and stable surface. These included a ¾-in. limestone aggregate, a polyurethane stabilizer, and one of the polymer stabilizers. The researchers concluded that a trail composed of an all-aggregate material, when constructed to specified parameters, could be maintained with little or no maintenance as a firm and stable surface. However, they also identified areas where further research is needed.

  • A rotational penetrometer was used to measure the firmness and stability of the test trail segments.

    Credit: The National Center on Accessibility

    A rotational penetrometer was used to measure the firmness and stability of the test trail segments.
For more on the study its measurement methods, click here to read the Access Board press release. By the way, if you’re not already signed up for updates from the Access Board, I suggest that you get on their email list. It helps you stay informed on all of the agency’s activities.

I strongly recommend this report to anyone involved in designing trails. It includes excellent photos demonstrating the different application processes, and the final analysis of each approach for accessibility, durability, maintenance, etc. What I like is its thoroughness. It includes charts, outcomes, and surveys from trail managers nationwide about the surface materials, treatments, and their effectiveness. The report is 158 pages long and well worth your time to download and read.

Wishing you all a great spring, now that it seems to be upon us!