Looking at the Edge of Safety

A child comes flying off a slide and hits the ground running. Suddenly the child stumbles and hits his or her head on the stretch of concrete edging that surrounds the entire playground.

At the same time on a similar playground, another child comes flying off a slide and hits the ground running. Suddenly, this child also stumbles and falls, but doesn't hit their head. What caused two similar incidents to turnout so different? For answers to this question you must enter . . . "The Use Zone."

To help us along on our journey through "The Use Zone," we will be guided by the U.S. Consumer Product Safety Commission's "Handbook for Public Playground Safety."

The use zone is an area under and around the equipment where protective surfacing is required. Other than the equipment itself, the use zone should be free of obstacles that children could run into or fall on and thus be injured. The CPSC has recommendations for use zones for different types of playground equipment, ranging from stationary equipment, to slides, to composite play structures.

Before we look at the use zone and how that can help with safety, we should take at look at why concrete edging is used in playground design. First, edging defines an area and allows Landscape Architects a chance to include curvilinear designs in a playground. There is also a practical use for it because it contains loose fill material. But because it is a hard material there must be a balance between the aesthetics, practicality and the safety of concrete edging.

"Concrete edging should be at least beyond the use zone," said Donna Thompson, Director of the National Program for Playground Safety. "And it should be further than that if things are extended out, but it should be at least that far."

Jonathan Dreyfuss, C.P.S.I., of Fundamental Playscapes in Ann Arbor, MI tries to steer clear of using concrete edging when he designs a play area.

"I don't see the benefit of it except from an adult aesthetic," he said. "In terms of the play value there is zero. I look at the play value and whether or not there is a long term maintenance issue, and that can be accomplished by any number of materials. But concrete edging allows for curvilinear borders which other materials don't. That's the real benefit of it."

Dreyfuss added that one place where edging could be beneficial is when it is used with plantings along the perimeter of a playground. While the edging holds back material, the child has the visual cue of the plantings so they know they are not supposed to go through the planting area.

"It is a visual message being sent by those combined objects as an area they are not to go through," he said. "In that application I think that is the perfect use. Outside of that you have to evaluate the benefits."

Now, here are some CPSC guidelines for the use zone in regards to various play equipment that may be helpful when designing a play area where concrete edging may be involved.

Stationary Equipment (excluding slides)

The use zone should extend a minimum of 6 feet in all directions from the perimeter of the equipment.

The use zones of two stationary pieces of playground equipment that are positioned adjacent to one another may overlap if the adjacent designated play surfaces of each structure are more than 30 inches above the protective surface (i.e., they may be located a minimum distance of 6 feet apart). If adjacent designated play surfaces on either structure exceed a height of 30 inches, the minimum distance between the structures should be 9 feet.

Slides

The use zone in front of the access and to the sides of the slide should extend a minimum of 6 feet from the perimeter of the equipment. However, this does not apply to embankment slides. But, the following recommendation applies to all slides, including embankment slides.

The use zone in front of the exit of a slide should extend a minimum distance of H + 4 feet where H is the vertical distance from the protective surface at the exit to the highest point of the chute. No matter what the value of H is, the use zone should never be less than 6 feet but does not need to be greater than 14 feet. The use zone should be measured from a point on the slide chute where the slope is less than 5 degrees from the horizontal. If it cannot be determined where the slope is less than 5 degrees from the horizontal, the use zone should be measured from the end of the chute.

The use zone in front of the exit of a slide should never overlap the use zone of any other equipment.

Single-Axis Swings

Because children may deliberately attempt to exit from a single-axis swing while it is in motion, the use zone in front of and behind the swing should be greater than to the sides of such a swing. It is recommended that the use zone extend to the front and rear of a single-axis swing a minimum distance of twice the height of the pivot point above the surfacing material measured from a point directly beneath the pivot on the supporting structure. The use zone to the sides of a single-axis swing should follow the general recommendation and extend a minimum of 6 feet from the perimeter of the swing structure in accordance with the general recommendation for use zones. This 6 foot zone may overlap that of an adjacent swing structure.

The use zone to the front and rear of tot swings should extend a minimum distance of twice the height of the pivot point measured from a point directly beneath the pivot to the lowest point on the occupant seating surface when the swing is occupied.

The use zone to the front and rear of single-axis swings should never overlap the use zone of any other equipment.

Multi-Axis Swings

The use zone should extend in any direction from a point directly beneath the pivot point for a minimum distance of 6 feet + the length of the suspending members. This use zone should never overlap the use zone of any other equipment. In addition, the use zone should extend a minimum of 6 feet from the perimeter of the supporting structure. The 6 foot zone may overlap that of an adjacent swing structure or other playground equipment structure in accordance with the recommendations for stationary equipment.

Merry-Go-Rounds & Spring Rockers

The use zone should extend a minimum of 6 feet beyond the perimeter of the platform. This use zone should never overlap the use zone of any other equipment.

The use zone should extend a minimum of 6 feet from the "at rest" perimeter of the equipment.

Composite Play Structures

The above recommendations for individual pieces of equipment should be used as a guide in establishing the use zone around the perimeter of a composite play structure.

In playgrounds where occasional overcrowding is likely, a supplemental circulation area beyond the use zone is recommended. Whether to provide such a supplemental circulation area should be based on the professional judgment of the playground designer and/or owner/operator.

Layout and Design of Playgrounds

When planning a new playground, it is important to consider hazards or obstacles to children traveling to or from the playground. A barrier surrounding the playground is recommended if children may inadvertently run into a street. Such a barrier should not prevent observation by supervisors. If fences are used for such barriers, it is recommended that they conform to applicable local building codes.

When selecting a site, consideration should be given to slope and drainage, especially if loose-fill surfacing materials are going to be installed. While a gentle slope may aid in drainage, steep slopes could result in loose fill materials becoming washed away during periods of heavy rain. Such sites may require re-grading.

Locating Equipment

The playground should be organized into different areas to prevent injuries caused by conflicting activities and children running between activities. Active, physical activities should be separate from more passive or quiet activities. Areas for play equipment, open fields, and sand boxes should be located in different sections of the playground.

In addition, popular, heavy-use pieces of equipment or activities should be dispersed to avoid crowding in any one area. The layout of equipment and activity areas should be without visual barriers so that there are clear sight lines everywhere on the playground to facilitate supervision.

Moving equipment, such as swings and merry-go-rounds, should be located toward a corner, side or edge of the play area while ensuring that the use zones around the equipment are maintained. Slide exits should be located in an uncongested area of the playground. Use zones for moving equipment, such as swings and merry-go-rounds, and at slide exits should not overlap the use zone of other equipment, regardless of height.

Composite play structures have become increasingly popular on public playgrounds. Care should be taken to ensure that the play and traffic patterns of children using adjacent components on composite structures are complementary.

Tripping Hazards

All anchoring devices for playground equipment, such as concrete footings or horizontal bars at the bottom of flexible climbers, should be installed below ground level, beneath the base of the protective surfacing material, to eliminate the hazard of tripping. This will also prevent children who may fall from sustaining additional injuries due to exposed footings.

Low retaining walls are commonly used to help contain loose surfacing materials. In order to minimize trip hazards, retaining walls should be highly visible and any change of elevation should be obvious. The use of bright colors can contribute to better visibility, according to CPSC.

"The thing that becomes important is that there is a contrast between the outside of the play area and the play area itself," Thompson said. "Some schools have gone to coloring those edges so that the kids can clearly see them.

"One of the 'sticky wickets' on that is in regards to standards, because there is no standard height for edging and kids do trip over them all the time. We really don't know how high it needs to be because in preschool areas you are dealing with kids who are 2-5-years-old and their ability to pick up their feet and put them down is different from 2 to when then are 5. In school age you are dealing with kids 5-12, and there are a lot of developmental differences there."

Thompson said that she does know of schools that have experimented with contrasting colors for the edging and the playground and from what she has heard, the number of injuries at those schools have dropped.

The intended user group should be obvious from the design and scale of the equipment according to CPSC. Some playgrounds, often referred to as "tot lots," are designed only for preschool-age children, so separation is not an issue.

In playgrounds intended to serve children of all ages the layout of pathways and the landscaping of the playground should show the distinct areas for the different age groups. These areas should be separated at least by a buffer zone, which could be an area with shrubs or benches. If concrete edging is used in the buffer zone it is recommended that the area be a contrasting color from other elements in the play area.

"Sometimes designers get too caught up in the design component and lose site of the practical element which is that you have spaces for children, some of whom are not able or capable of looking where they are going," Dreyfuss said. "And these spaces need to be designed for these kids.

“It is important to look at these spaces in terms of how they are really going to be used and keeping them safe.”