Research: A Longitudinal Study of Playground Surfaces

October 21, 2013

Jennifer K. Skulski, CPSI
National Center on Accessibility, Indiana University – Bloomington 

In 2008, the National Center on Accessibility (NCA) at Indiana University initiated a longitudinal study of playground surfaces with research funding by the U.S. Access Board.  The purpose of this longitudinal study was to evaluate a variety of playground surfaces, their costs, and their ability to meet accessibility requirements while documenting deficiencies that arise upon initial installation or those that might require maintenance after a 3-5 year period of use.  Surfaces for the study were limited to poured in place rubber (PIP), rubber tiles (TIL), engineered wood fiber (EWF), shredded rubber (SHR), and hybrid surface systems (HYB).

The First Year Findings (PDF) were published in 2011.

The Final Report (HTML) (PDF) was released in October 2013.

The research questions include:

  1. How well do various playground surfaces meet the accessibility requirements upon installation and over a five-year period? 
  2. What are the costs for the various playground surfaces?
  3. What accessibility issues arise out of initial installation? 
  4. What accessibility issues arise out of long term use and require additional maintenance?

The research design for this study has been in development since 2005 with input from a national advisory committee.  Approximately 35 playground sites were recruited for participation.  Data collection concluded in September 2012.  All of the playground sites were located in public parks owned/operated by 16 different municipalities from Indiana, Illinois and Michigan.  Sites included either neighborhood playgrounds or those located in regional parks.  The 16 participating municipalities operated anywhere from 4 to 53 playgrounds each.  The average number of playgrounds operated by a municipality was 24.  None of the playground owners were coming into the study as “first time” owners.  All of the owners had a history of managing playgrounds.  They considered themselves somewhat knowledgeable of playground surface issues and eager to learn how they could improve upon their playground surface maintenance efforts for costs savings.

The most valuable lesson to be learned from this longitudinal study, it is that there is no perfect playground surface.  Even within 12 months of installation, each type of surface had some type of issue or series of issues that affected the product’s performance and contribute to the necessity and frequency of surface maintenance to assure accessibility and safety for use by children on a daily basis.  A playground surface with poured-in-place rubber had a use zone found in non-compliance with the ASTM standard for impact attenuation.  Playgrounds surfaced with tiles were observed with puncture holes, buckling and separating seams that created openings and changes in level on the accessible route.  Inaccessible routes with undulating surface material were identified at playgrounds with engineered wood fiber.  A build-up of static electricity was found at one of the hybrid surface locations.  Each occurrence and event was weighed and balanced with the product’s feature advantages and drawbacks. 

Other study findings outlined in the NCA report, “A Longitudinal Study of Playground Surfaces to Evaluate Accessibility” include:

  • Playground sites with loose fill engineered wood fiber were found to have the greatest number of deficiencies affecting the accessible route to play components, such as excessive running slope, cross slope, and change in level.  These deficiencies were also found to be more prevalent within the first year of installation;
  • Deficiencies, such as excessive running slope, cross slope, changes in level, and openings for poured-in-place rubber, tiles and hybrid surface systems began to emerge 24-36 months after installation;
  • Within 12 months of installation, playground sites in the sample with loose fill engineered wood fiber were found to have the highest values for firmness and stability, indicating greater work force needed to move across the surface, while playground sites with the unitary surfaces like tile and poured-in-place rubber were found to have the lowest values for firmness and stability– indicating less work force necessary to move across the surface;
  • In some instances, surface materials were not installed according to manufacturers’ recommendations to achieve an accessible surface;
  • A playground surface with fewer accessibility deficiencies and a lower measurement for firmness and stability did not necessarily meet the safety standards for impact attenuation; and
  • Surface cost for material cannot serve as an indicator or predictor of performance.

Read the Final Report  (HTML) (PDF) for a discussion of the research design, findings, and implications.

A free webinar presenting the research findings will be held on Thursday, November 7, 2013 and archived for viewing on demand through the AccessibilityOnline program.