Sustainable Cities™

Chicago: the greenest road in the USA

In spring 2013 Cermak Road in Chicago was voted the greenest, most sustainable road in the USA. The award is the result of the city’s focused investment in the implementation of countless green technologies and green solutions on this route.

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Cermak Road Foto: Chicago Department of Transport (CDOT)

The windy city has experimented with sustainable solutions in an effort to deal with the increased number of storms, torrential downpours and extreme temperatures, which it is experiencing. The holistic solution chosen for the project in Chicago is allegedly the first of its kind in the USA. One element of the project is the permeable surface, which has been applied to the road in the Pilsen industrial district. The idea of this permeable surface is to relieve the local sewage system during torrential rain. As an example of the project's holistic philosophy, this solution has been combined with additional measures, which include rain beds and the discharge of water from the gutters of the houses down into green ditches.

Other examples of initiatives, which contribute to a cleaner environment, include the road's LED street lighting, which is operated by a combination of wind and solar energy, and seating blocks, which are made from smog-eating or self-cleaning cement. 23 % of the construction materials (asphalt and concrete) are recycled from other projects, and after the reconstruction of the road, 60 % of the construction waste was recycled in other structures and construction projects. The project chose plants, which can withstand drought, in order to avoid excess waste of water during the summer. 

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Photos: WBEZ/Caroline O'Donovan

Cheaper - in terms of both construction and maintenance

The 3.2-km stretch of road, which looks like an ordinary road, cost $14 m to build. This is 21 % less than a traditional road reconstruction. In addition to costing less, the road should also be cheaper to maintain and will allegedly last for up to 100 years. The construction process was also a learning process, which has inspired the city to embark upon similar projects in the future. Many more trees have been planted, public transport has been improved and several cycle lanes have been implemented together with a bicycle-sharing system. Since the excellent example of Cermak Road, the permeable surface materials have been used in nearly all subsequent road reconstructions.

The smog-eating and partially self-cleaning cement, which was used in the project, is supposed to remain white despite pollution and exhaust fumes. The material is Italian, developed on the basis of research conducted by the Vatican aimed at the construction of churches. The secret of the cement's capacity to break down exhaust gases is the fact that the material is treated with titanium dioxide (TiO2). When the treated surface is affected by sunlight it starts a reaction, which breaks down the nitrogen dioxide in the exhaust gases. According to the Italian studies, this capacity will lead to a situation, in which the air at a distance of up to 2.5 metres will be cleaner than above an untreated surface.

Thursday, August 22, 2013 / By Nina Kirstine Busk

Last updated Monday, April 14, 2014