Cohousing-L Mailing List: Re: Sidewalk material/accessibility

[Design Coalition Inc. (designco]

There ARE a number of paving options besides concrete and asphalt that are
wheelchair- AND environmentally- friendly.  We've used 'choker' for
accessible paths and patios. Choker is what it's called locally; it's
basically limestone fines.  Around here we've got plenty of limestone, and
it's crushed to make different sized gravel.  The tiny leftover pieces (in
a pile, it looks like coarse sand) are actually kind of tetrahedral shaped,
and when compacted they lock together nicely to create a reasonably hard,
natural paving.  Wheels roll well, it's somewhat porous, it has low
embodied energy, it's not-toxic.  Our parks systems use it for bike paths,
and our City accessibility watchperson has given the material an OK for
accessible paths.

A few caveats:  It must be installed correctly, with side containment and
good compaction.  Prolonged rain will soften it (tho' it dries quickly if
installed to drain well), and torrents directly across can erode it.  So
sometimes it may have to be re-raked and re-graded.  It freezes in winter,
like unto concrete, and so can be shoveled clean of snow and chipped clear
of ice.  But it's not the impervious, hard,
put-it-in-and-forget-about-it-forever material that concrete is.

Of course, not all paved surfaces are equal, nor should they be. A garden
path, a terrace with tables & chairs, a fire lane, a main circulation walk,
all have different requirements.   Use what's appropriate for the intended
service.

Lou Host-Jablonski, AIA
Design Coalition Inc., Architects
2088 Atwood Avenue
Madison, WI  53704

LouH-J [at] execpc.com

608/246-8846 (voice)
608/246-8670 (fax)