This is
the VOA Special English Development Report.
An
environmental project in the American city of Chicago, Illinois, could offer
ideas for cities around the world. The project is gaining ground -- and it is
the ground itself that is involved.
 |
| An environmentally friendlier ''green alley'' in Chicago |
Two
years ago, the city’s Transportation Department launched a program to improve
surface wear and reduce flooding in alleyways. An alley is a narrow roadway
through the middle of a block.
The
Green Alley program uses new technologies to help protect the environment, save
energy and reduce heat in the city.
Chicago has three thousand kilometers of
public alleys -- about thirteen thousand alleys in all. Many were built without
connections to Chicago’s combined sewer and storm water systems.
Alleys
are being rebuilt or renewed with permeable pavement. The material is hard
enough to support the trucks that use the alleys to collect trash. But
permeable pavement has openings that let water pass through the surface and
into the soil below.
Specially formulated asphalt, concrete
or pavers can be used. City officials say the material lets as much as eighty
percent of rainwater pass through.
Also,
sunlight bounces off the light-colored surface, so it stays cool on hot days.
Densely built areas of cities trap heat. This is known as the urban heat-island
effect.
The Green Alley program also uses
recycled materials. And it uses energy-saving streetlights. These direct light
downward to reduce light pollution at night.
Research for the project began in two
thousand four. No businesses own any
patents on the materials used in the Green Alley program.
Not all
Chicago alleys need replacing. Program head Janet Attarian says sixty-two
alleys will have been renewed or rebuilt by the end of this year. City
officials are also starting to use the environmentally friendly technologies
for parking areas and low-traffic roads.
Permeable
pavement is not very good for roads with a lot of traffic. Too much weight and
travel over the material can damage it.
Within
six months of pouring Chicago’s first permeable concrete alley, the cost of the
new concrete had dropped more than sixty percent.
Chicago has "more miles of alleyways than any other
city in the world," says Mayor Richard M. Daley in the Green Alley
Handbook. We'll post a link to the
program at voaspecialenglish.com.
And that’s the VOA Special English
Development Report, written by Jill Moss.
This is
the VOA Special English Development Report.