Outdoor areas that have been identified that create difficulty for social distancing during their normal use such as playgrounds or outdoor stairwells are being signed asking for mask use. If two members of the public are heading in opposite directions on a 100m stairwell and they meet in the middle neither has the ability to safely distance and the assumption is that they are not from the same household so the request to the public is that before embarking up that stairwell they are masked.
The same request is being asked at all public playgrounds for the same reason, it is unlikely that families or children in the normal course of playground use would be able to give 2m of distance to one another. It is also assumed that more than one household group will want to utilize the playground simultaneously. By wearing the masks users are following the guidelines to do so when distancing is not possible. This also helps to limit some exposure to touchpoints such as railings or other surfaces.