Now, it acts as a valuable learning and teaching tool about how streetscapes can play a role in advancing citywide sustainability.

A section of the industrial avenue is outfitted with all manner of green technologies and landscape interventions: energy-efficient lighting, bioswales, drought-tolerant plants, and permeable pavement, among others.

"Mayor Emanuel's vision is to make Chicago the most livable, competitive, and sustainable city. We do that by working internally to ensure that the city is thoughtful about about operations and resources—driving energy efficiency and driving sustainable infrastructure. We also accomplish his goals through partnerships—working with a lot of outside organizations to support to the full reach of the city and by engaging more people," says Karen Weigert, Chicago's chief sustainability officer. Sustainable Chicago plan consists of seven action points: economic development and job creation; energy efficiency and clean energy; transportation options; water and wastewater; parks, open space, and healthy food; waste and recycling; and climate change.

We talked to Weigert and Janet Attarian, the city's "Complete Streets" program director, about the "greenest street in America" and how the Pilsen Sustainable Streetscape acts as a microcosm of the Windy City's larger sustainability plan.

What's the 30 second elevator pitch for Cermak Road?

Attarian: Of what it's about or why it should be done? This might be two 30-second elevator pitches!

It should be done for a whole host of reasons, but they all really get at the two main responses to climate change: adaptation and mitigation. Adaptation certainly is a no-brainer when it comes to our infrastructure, and that's been proven to us again and again in the last couple of days. We can't have roads go out of service because they've flooded or buckled. We can't have vegetation die because we have a drought. And the list goes on and on. And, of course, we need to maintain a high quality of like because that's our job as a good city—that's how we attract and retain business.

This job in particular was done in an industrial corridor. It's an area where we've made a commitment to retain industry and it's really important that industry has functioning infrastructure. On the other hand, it's also an area that abuts a thriving residential community, a high school, a park, and retail. They deserve to have a street that meets their needs and isn't an industrial bywater, if you will.

Weigert: It's a pretty interesting project overall from a science, engagement, and building sustainability standpoint. It's really kind of fun. The street connects right to the front of a high school. One of the features of sustainability is to enhance the quality of life and experience. We enhance long-term sustainability by ensuring we're being thoughtful about taxpayer resources and ensuring our infrastructure works. But we're also creating very beautiful spaces. It's a great example of placemaking today in an infrastructure that will be much better for us tomorrow.

What does it mean to have a "complete street"?

Attarian: A complete street addresses mode hierarchy [pedestrians, transit, bicycles, autos], environmental services, and placemaking. That's how you get great streets and that's what we really mean by the "greenest street in America."

We also mean that it addresses environmental services like no other street has, but it goes way beyond just stormwater management and energy efficiency. It's also about the fact that we have to get a much better return on our investment. If you just fix infrastructure, or you just did any one move, your return on your investment is pretty limited. But when you get these synergies, which is what sustainability is really about, every dollar you've invested becomes much greater than if you just resurfaced the street, for example.

Sustainability means taking a really holistic view and hitting the social, the environmental, and the economic balance. So backtracking a little bit, you mentioned that the street was in an industrial area and adjacent to a high school. For those of us who are unfamiliar with Chicago, can you describe the characteristic of the street as it was before and what it's like now?

Attarian: It was rough. The light poles were old, aerial wires tilted in every direction. One side of Cermak road is an active rail line. There are also bus stops. People had to walk through the mud. The sewer line was 100 percent clogged—there was no infiltration at all. You'd be walking along the sidewalk and there'd be holes. It was a street that needed a lot of love from an infrastructure perspective.

From the social infrastructure side, it had—and still has—thriving industry. This is the place where the McCormick reapers were made. It has a thriving hispanic community very centered around the arts and family. You have these two very vibrant but very different things that came together at this edge condition that hadn't received a lot of love for a long time. Cermak is a Class Two truck route—this is not your little side street that you turn into a nice green pilot. This is serious infrastructure.

Why was it important to choose this thoroughfare over a smaller street to rehabilitate?

Attarian: It's important for a number of things. When you're piloting infrastructure like this, you really want to understand what works and what doesn't work. You don't want to just know the answer in the easy places. You want to know the answer in the hard places. When you have a road like Cermak that needs a lot of work to bring its infrastructure up to date, why not do it green?

One of the things I'm proud of in this project is that its aesthetic works in this type of condition and environment. That's another part of what we're trying to understand through these types of projects. I think it's been very successful in creating a transitional area and addressing all the various constituents that we have at the table.

Do you think this is the future of all Chicago's streets? Or is it more for the case study element of this particular stretch of land.

Attarian: This is for all Chicago streets. But that doesn't mean that all streets will be a Cermak. Context is incredibly important. We've done the green alley pilots, we've piloted smaller streetscapes. We've done enough pilots that we now know that we can make this business as usual. That's our next step and what we plan on doing.

Cermak has been an ongoing program. How long ago did it start and when will it be completed. Is it something that will ever be "completed"?

Attarian: That's a good question—is anything ever done? Well, I have to say the first germination of the first idea went back to 2004 but we didn't even have a site. We just had this concept that we said, "What does it mean to have the equivalent of LEED Platinum in a street?" We sat down and tried to figure this out. What does it mean? What would apply? What are the right types of categorized and environmental services that you're talking about when you talk about a road? We had a notion of what we were working on on a conceptual level and when this project came about, we said, this might be a really good one to try it on because we knew were were going to do a lot of infrastructure improvements.

Weigert: In this example, we did a lot of things in an integrated way. It's unbelievably comprehensive when you talk about the materials and the lighting and the surfaces. Many of those things are in place in other parts of the city now. It's not that though we were looking for one place to test a bunch of different things. This just happens to be an unbelievably integrated example in which you can bring it all together. You can find hundreds of green alleys thanks to Janet and the team here.

Attarian: We were learning the whole time we were designing this. We were were doing green alleys at the same time, too. So we have permeable pavers on almost every streetscape we've done in the last five years. We've changed our lighting over time, we still have a ways to go, but we've begun the process of making lighting more efficient and dark-sky friendly.

Weigert: We looked at plants and the trees that we put in and made sure that they were appropriate for potential changes in the weather. There are some things that are pretty unique about this project. I know the photocatalytic elements are not exactly widespread, but from a comprehensive perspective it's an example of things we want to see all over the city of Chicago.

Attarian: And some of the things about this project you don't see. It was the first project where we made the contractor track, like a they would for a building, where the recycled waste was going, the recycled content they were using, if materials were extracted and manufactured locally, what types of fuel they used. So those things, in some ways, are more radical than the things you see because those are the game changers for the industry. They have a ripple effect.

Tell us about the partnerships that you guys have been working on to get new technologies developed.

Attarian: The industry has been a great partner for us. Vulcan Materials stepped up to the plate and they made a bunch of recycled aggregates for us that didn't exist in the market before this project. And the company went to the effort to get the materials certified. So instead of just meeting our goal of 20 percent recycled content, we were able to reach 40 percent recycled content. And so those things are game changers because once the company goes through the effort of making the equivalent of a Class A recycled aggregate, private industry gets to use it too.

Weigert: We like to think of the multiple benefits of sustainability and certainly strengthening the competitive capacity of the local supply base is an example. We want to see more innovation in Chicago and when we can partner on that innovation, that brings long-term benefits and a great use of taxpayer dollars because we're reducing our long term cost structure. Its a win-win.

Speaking of new technology, the photocatalytic—or "smog-eating"—cement you used to pave the road has gained a lot of attention. It's something that's been used in Europe and in buildings. How did you decide to use the material and why it was important for Chicago to be among the first cities in the US to do so?

Attarian: The issue first came about because of albedo [a measure of reflectivity] and the urban heat island effect. We all talk about pavements and what their albedo is. However, reflectivity is talked about when the materials first go in. The problem with pavements is that they get driven on and parked on. Over time, they all move toward the same dirtiness level. It's great to say that we have a high reflectivity going in but the issue becomes maintaining that reflectivity over time.

The idea of a self-cleaning pavement becomes very appealing in that way. The pavement doesn't only self-clean its surface, but it can actually remove pollutants from the air up to eight feet, depending on conditions. Pedestrians and cyclists are in the eight-foot envelope and then you start to think about the fact that you're on a heavy truck route, and it's an industrial area, and it's a dirty site. It's heavy industry, it's not a pristine area. This is a place with trucks and all sorts of things going by. But then again you look at the details of the product. It can be very very expensive if you just want to put it in for your sidewalk.

What's the price difference per square foot if you were to use this versus something traditional?

Attarian: If you were to do a full-scale concrete, it would be a lot. More than you'd be willing pay. That doesn't make sense. So we thought that the pavers could do a base mix and a top half-inch with the photocatalytic mix. Now that starts to make sense. We approached a paving company and asked if it was something they'd like to do. A manufacturer in Illinois stepped up and said that this was something that they'd be willing to do. They did the testing and the mixes. We partnered them with Italcementi [the manufacturer of the photocatalytic cement] and they came up with a product. It ended up costing only one additional dollar per square foot to do it this way.

Weigert: This is a really fabulous example of what we want to do in Chicago. We want to make every decision a sustainable decision and we want to bring sustainability into all corners of the city. It can be experienced in lots of different ways but it has a great value proposition and people can experience that when they're on those streets.

For more on the Chicago's Complete Streets program, the Atlantic Cities offers up an analysis of the guidelines here or read the original document in its entirety here.