IRVING PARK — Last time anyone checked, Metra and the Kennedy Expressway weren't going anywhere.

Neither are their viaducts, which create pedestrian barriers, bisect neighborhoods and disrupt commercial corridors.

"This entire community is carved up by viaducts," said Marlena Ascher, president of the Old Irving Park Association.

Since 2003, the association has been working to turn its liability into an asset, preferring to view the viaducts as a blank canvas for public art.

This summer, "Positive Babel" — conceived by artist Tony Sparrow and executed by a team of volunteers and professionals — became the 10th and 11th viaduct murals sponsored by the association. (The association counts each wall — north wall, south wall, for example — separately.)

"It's a simple solution to create a dramatic difference in how people perceive their community," said Anna Zolkowski Sobor, association vice president.

"Positive Babel," at Keeler Avenue and Irving Park Road, represents something of a departure for the association.

Over the years, the group has opted for complex, collage-style designs. The riot of images is intended to give passers-by, namely drivers, an overabundance of visual detail to entertain them while they're stuck at traffic lights. The montages also serve to deter vandals.

"Simpler designs attract more graffiti," said Ascher — just one of the many lessons the association has learned from experience.

By contrast, "Positive Babel" is situated in a "drive-by" viaduct, and Sparrow's clean, three-color concept is meant to be easily "read" by people as they zip past the mural at 30 to 40 miles per hour.

He conceived of the idea, which features more than 70 landmarks from around the world, after spending time immersed in the environment surrounding the mural's future home.

"It's such a commuter area," said Sparrow, whose mural work can also be seen at Addison and Avondale. "I was hearing all these different languages, seeing a lot of different people."

At the same time, Old Irving Park is known for its historic architecture, which Sparrow became enamored with at an early age.

"I grew up in Avondale. My mom, when we were younger, used to drive us through Old Irving Park to look at all the beautiful houses," he recalled.

Sparrow took those two themes — diversity and architecture — and ran with it. Among the iconic images depicted in the mural: the Pyramids of Egypt; Brazil's Cristo Redentor; the Kremlin; the Statue of Liberty; the Sydney Opera House; Big Ben; Cambodia's Angkor Wat; and the skylines of Stockholm and Oslo.

"We've had people say, 'Thanks for putting in a mosque, we're usually eliminated,'" said Sparrow.

Local touches, according to the artist, include reeds intended to represent the Chicago prairie and a light blue paint that matches the color used in the Chicago flag.

Another unique feature: "Positive Babel" is the first Old Irving Park mural to incorporate a viaduct's pillars. The effect creates a picture frame of sorts for the mural's images and passers-by, drawing them into, if only momentarily, the work of art, Sparrow explained.

Where the association's first mural took a year to bring to fruition, according to Ascher, "Positive Babel" was approved in late spring and was completed in just two weeks time in late July.

"At a certain point, we'd developed a 'how to do a mural' manual,'" said Sobor.

The association has secured standing permissions from Union Pacific and has streamlined the design process. Where the group used to hold contests and cast a wide net for proposals, they now work with select artists whom they give a fair amount of creative control.

"We're not going to micromanage," Sobor said.

"It's more like filmmaking," said Sparrow, comparing his role to that of a director.

The association, in this analogy, would be the producer: coordinating logistics; cutting deals with neighboring businesses to donate food to artists, as well as all-important bathroom privileges; and, most critically, funding the project, mainly in the form of paying for paint.

"Positive Babel" soaked up roughly 30 gallons and cost approximately $2,500 per mural wall. The artists' labor is 100 percent free.

Sparrow, who lives in nearby Independence Park, recruited a core group of his peers to contribute to the mural — many of them immigrants or the children of immigrants, in keeping with "Positive Babel"'s theme.

"He watched, who were the artists who came early and stayed late" on other projects, said Ascher.

Artist Jerry Rogowski, a native of Poland, was a daily fixture at the "Positive Babel" site. Rogowoski took time away from his work as an independent contractor to see the mural through to completion, even when that meant suffering through a heat index that topped 100 degrees.

"You paint faster," joked Rogowski, the man behind the brushwork used to create the intricate girding of the mural's Eiffel Tower.

"I climbed it, I conquered it, I painted it," he said.

For Sparrow, 46, the joy of seeing his vision come to life had as much to do with the process as the end result.

"I'm more proud that I get to work with my friends," he said.

A self-taught artist, Sparrow has spent the last 16 years as creative director and CEO of a local advertising agency. His passion for murals has given him cause to take a step back and reevaluate his priorities.

"For me it's a little bit about legacy. It's why I started getting into public art," said the father of two. "What are my kids going to remember — some commercial I made?"

But as he put the finishing touches on "Positive Babel" — including the "glamorous" job of hanging spikes to keep pigeons and their acidic, paint-destroying droppings at bay — Sparrow was hardly in the mood to reflect on his achievement.

"What's next?" he said. "What's the next wall?"