In the alley-center infiltration approach, permeable material
(asphalt, concrete, or pavers) is placed in the center of the
alley and high-albedo concrete is placed along the outer edges.
This way, water soaks through the center of the alley, but truck
tires roll on top of the stronger pavement. Each of Chicago's
four pervious-pavement designs can be tweaked to fit just about
any alley in the city. This is an example of full-alley
infiltration using permeable pavement. Source: Chicago DOT
Here's a little-known fact about Chicago: The Midwest city has
more miles of alleys—1900 in all—than any other city in the
world. That's the equivalent surface area of five mid-sized
airports. That's also 3500 acres of impermeable surface in a
city that's committed to going green. But going green isn't the
sole reason for the city's $900,000 alley-renovation pilot
program, funded by general funds. “One of residents' biggest
complaints is flooding,” says Janet Attarian, project director
of the city's streetscape and urban des