Board Sponsored Study Completed on Natural Trail Surface Materials

  Person applying stabilizer to trail segment

Most trail segments tested were treated with a stabilizer.

  trail segment with rotational penetrometer in foreground

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

A study sponsored by the Access Board on the accessibility of trail surface materials was recently completed by the National Center on Accessibility (NCA) at Indiana University. The project 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. 

Researchers created test trail segments that ranged in length from 30 to 200 feet at Bradford Woods, a 2,500 acre natural environment in Martinsville, Indiana. The study included three trail segments with a crushed limestone surface and eight with soil surfaces that were treated with organic or natural by-product stabilizers. The limestone surfaces involved different aggregate sizes (1/4” maximum, 3/4” maximum, and a combination of both in a dual layer) that were at least six inches deep and compacted to a rate of 90%. The other surfaces tested were created with stabilizers applied directly to the soil or mixed with an aggregate. The stabilizers tested included polyurethane, organic plant matter, two kinds of polymer, and four types of vinyl acetate copolymer applications.

The project team used a field test device known as a rotational penetrometer to measure surface firmness and stability. This instrument utilizes a wheelchair caster and a spring loaded gauge to replicate the propulsion of a wheelchair across a surface. Penetration measures determine the degree of firmness, while stability is gauged by the horizontal displacement of the surface material from the side-to-side rotation of the caster. Measurements were taken at five different locations along each of the 11 test trails every 3 or 4 months over a 51 month period. In addition to these measurements, researchers noted changes observed in the trail surfaces.

Based on the values assigned to the firmness and stability measurements, the findings indicate that several types of surface materials tested, when installed according to the study’s protocols, maintained a consistently firm and stable surface. These included the 3/4” size limestone aggregate, the polyurethane stabilizer, and one of the polymer stabilizers. In addition, the researchers concluded that based on the study’s data, “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.

In a second phase of the project, researchers conducted a nationwide survey of trail managers to gather information on types of surface materials and treatments used and their effectiveness. Among 39 trails reviewed in the survey response, most were composed of native or natural soils or crushed rock and only a small portion (less than 8%) involved some type of stabilizer.

These and other conclusions are discussed in a report on the project, “National Trail Surfaces Study: Final Report,” which is due to be published on NCA’s website next week. For more information on the project, contact Sherril York, Ph.D., Executive Director of the NCA, at This email address is being protected from spambots. You need JavaScript enabled to view it., (812) 856-4422 (v), (812) 856-4421 (TTY), or Bill Botten of the Access Board at This email address is being protected from spambots. You need JavaScript enabled to view it., (202) 272-0014 (v), or (202) 272-0073 (TTY).

Board Names New Compliance Specialist Following Staff Retirement

Peg BlechmanPeg Blechman, an Access Board Compliance Specialist for over 16 years, is retiring from government service. As a member of the agency’s Office of Compliance and Enforcement, she investigated complaints filed with the Board under the Architectural Barriers Act (ABA) which requires access to facilities that are designed, built, altered, or leased with federal funds. Her cases included facilities and sites that she investigated through the U.S. Postal Service, the Defense Department, the Department of Veterans Affairs, and the Department of Transportation (DOT). Before joining the Board in 1997, she served at DOT’s Office of Civil Rights where she helped implement and enforce requirements of the ADA pertaining to public transportation. Prior to that, she designed and implemented education programs and accessible programs at the Smithsonian’s National Museum of African Art and worked in photographic services and reproduction rights at the National Gallery of Art. Her service in the federal government spans 30 years. She has a J.D. from the Columbus School of Law at The Catholic University of America and a Master of Arts in Museum Education from George Washington University.

Mario DamianiMario Damiani will succeed Blechman as a Board Compliance Specialist. He joins the Board from the U.S Department of Labor where he served as a Policy Advisor at the Office of Disability Employment Policy for over seven years. His work included development of national policies on accessible workplace technology and social media tools, provision of workplace personal assistant services and other reasonable accommodations, centralized accommodation funding, and the employment of individuals with disabilities by the federal government and its contractors. He also served as the Labor Department’s staff liaison to the Access Board. Previously, Damiani worked as an Attorney-Advisor at the Office of the General Counsel at the District of Columbia Department of Health where he provided legal counsel related primarily to the licensing and discipline of medical professionals in the District. He also worked as a law clerk at the District of Columbia Office of Bar Counsel where he assisted in the prosecution of attorney disciplinary matters involving members of the D.C. Bar, and at the District of Columbia Court of Appeals. Damiani completed a six-year B.A./J.D. Joint Degree Program at The Catholic University of America, earning Summa Cum Laude honors and election to Phi Beta Kappa as an undergraduate in the University’s Honors Program.

Upcoming Board Webinars

laptop with Access Board sealThe next webinar in the Board’s free monthly series will take place March 6 from 2:30 – 4:00 (ET) and will feature an open question and answer session with Board accessibility specialists on the ADA and the ABA Accessibility Standards, the Section 508 Standards, Medical Diagnostic Equipment and other Board rulemakings or activities. Participants are encouraged to submit questions in advance of the session through the webinar site. Questions also can be posed during the webinar.

Subsequent webinars in this series will cover:

For more information, including registration instructions, visit Archived copies of previous webinars can be accessed on this site.

Section 508 Best Practices Webinar Series
The Board, in partnership with the Accessibility Committee of the CIO Council, also conducts the Section 508 Best Practices Webinar Series. These webinars provide helpful information and best practices for federal agencies in meeting their obligations under Section 508 of the Rehabilitation Act which ensures access to electronic and information technology in the federal sector. The next webinar in this series will be held March 25 from 1:00 – 2:30 (ET). For further information, visit

DOJ Proposes Regulatory Revisions and Issues New ADA Guidance

DOJ sealThe Department of Justice (DOJ) has proposed changes to its Americans with Disabilities Act (ADA) regulations to implement requirements of the ADA Amendments Act of 2008. The ADA Amendments Act revises the definition of “disability” to more broadly encompass impairments that substantially limit a major life activity. In a recently published notice, DOJ proposes to add new sections to its regulations issued under titles II and III of the ADA to provide detailed definitions of “disability” and to make corresponding changes in other sections of the regulations. The notice is available for comment until March 31, 2014. Comments can be submitted through the website.

In addition, DOJ has released two new guides in its "ADA Requirements" publication series. "Wheelchairs, Mobility Aids, and Other Power-Driven Mobility Devices" provides guidance on DOJ’s ADA regulations regarding the use of wheelchairs and mobility aids, as well as other types of less-traditional powered mobility devices. "Effective Communication" explains provisions in DOJ’s regulations relating to communication access for people who have vision, hearing, or speech disabilities. Guidance on other ADA topics is also available on DOJ’s website.

For further information, contact DOJ through its ADA hotline at (800) 514-0301 (v) or (800) 514-0383 (TTY).

Institute on Disability Releases Annual Disability Statistics Compendium

Cover of the 2013 Annual Disability Statistics CompendiumIn December, the Institute on Disability at the University of New Hampshire released its Annual Disability Statistics Compendium, a web-based tool that compiles disability statistics published by various federal agencies. This resource includes disability statistics on employment, income, health care, benefits, and other topics.

Key findings from the 2013 Compendium indicate that the number of people with disabilities in the labor force has been nominally decreasing since 2008 and that currently the participation rate is 20.6%, versus a participation rate of 69.4% among people without disabilities. Among those with a bachelor’s degree or higher, the rate is 28.4% for people with disabilities and 76.1% for people without disabilities. Studies also show that the unemployment rate among people with disabilities is 13.4% while the rate among people without disabilities is 7.9%.

The Institute on Disability, which is part of the Rehabilitation Research and Training Center on Disability Statistics and Demographics, is funded by a grant from the U.S. Department of Education’s National Institute for Disability and Rehabilitation Research. Further information is available on the Institute’s website.


Access Currents is a free newsletter issued by the Access Board every other month by mail and e-mail. Send questions or comments to This email address is being protected from spambots. You need JavaScript enabled to view it. or call (800) 872-2253 ext. 0026 (voice) or (800) 993-2822 (TTY). Mailing address: 1331 F Street, N.W., Suite 1000; Washington, D.C. 20004-1111.