New CDOT Guidelines Require Sustainable Design in All Projects

Bioswale and curb extension
Under the new guidelines, water-filtering bioswales will become a typical component of street redesign projects.

The Chicago Department of Transportation continues to expand its role in building livable streets with the introduction of the Sustainable Urban Infrastructure Guidelines [PDF]. These guidelines address much more than transportation – including issues like water quality and economic development – because streets are not just for moving people and goods. CDOT intends this document to guide its own staff, sister agencies, and utility companies to incorporate green and sustainable components into all projects.

“Green infrastructure is not an option; it is an integral part of CDOT’s work and will be folded into every project,” reads one of the key principles in the guidelines. This doesn’t mean that every new alley will be made with permeable pavement, but that “something can be done on every project.”

The document meshes with the city’s goals to reduce its greenhouse gas emissions as well as the fiscal imperative to “do more with less.” Many of the requirements address things you see every day, like street landscaping and pedestrian islands, but the majority address less visible aspects of streets, like mixing asphalt at much lower temperatures (to reduce smoke and energy use), using recycled asphalt, and quantifying the environmental value of each project.

The guidelines lay out which requirements apply to which CDOT projects. For example, in a “Bike Facility Project,” designers must consider the “Passive Irrigation” requirement, which says that all landscape areas should be designed to absorb water runoff. Nowhere is this more evident than the bioswales along the Berteau Avenue neighborhood greenway, which clean, filter, and delay stormwater from entering Lake Michigan. The bioswales double as traffic calming curb extensions.

In another scenario, agencies building a rapid transit station should consider the “Beauty” and “Community” guidelines, which among other things require partnership with community groups to extend the project’s placemaking and complete streets benefits outside the construction area. CDOT released a complete streets design guidelines document this year and will soon produce the placemaking guidelines.

Informational materials
Beneath a solar and wind-powered streetlight, a display explains the Pilsen sustainable streetscape to the public.

Unfortunately these guidelines don’t hold any sway over private development, so a new parking garage in Rogers Park a block from the lake can be built without requiring that it be designed to capture and clean all of its runoff.

CDOT also wants these sustainable design concepts to reduce project cost. The Pilsen Sustainable Streetscape project featured nearly every concept one could think of. Visible features include a rain garden at Benito Juarez high school, bus stop shelters, and pedestrian islands, while designers implemented such hard-to-detect features as smog-fighting concrete and monitoring how much water the rain garden could process. Adding those elements actually seems to have cut costs. The project cost “21 percent less per block than the average per block cost of the 10 other similar projects bid” in 2011.

Cermak-Blue Island sustainable streetscape
Janet Attarian, CDOT complete streets project director, speaks at the ribbon cutting for the Pilsen sustainable streetscape a year ago.

The guidelines illustrate how these principles will come into play for three kinds of Chicago streets. One scenario is a “thoroughfare” street with mixed land uses — think Ashland Avenue. Before applying the guidelines, it has inefficient lighting and pedestrian areas that lack a sense of place. After applying the sustainable urban infrastructure guidelines, the street becomes cooler (by using reflective pavement), and has solar-powered bus shelters and design elements that identify the neighborhood. It will be interesting to see these guidelines applied to the Ashland BRT project so that as the street is transformed to move people faster, it also becomes a better community place with greater economic activity.

  • Anonymous

    “delay stormwater from entering Lake Michigan”

    Combined sewer means that if there’s enough rain, it’s not just stormwater entering Lake Michigan, it’s untreated sewage. Hopefully, enough of this kind of thing will get us to the point that we rarely release untreated sewage into the river and never into the Lake.

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