The word “bottleneck” is not typically associated with foot traffic along Chicago's miles of lakefront foot and bike paths. But according to Leo Schlosberg of Cary Concrete Products, the portion of trail that took walkers, joggers and bikers over the Diversey Harbor Inlet via an 84-ft.-long bridge was “one of the worst spots for pedestrians along the lake.”

Worse not only because of the potentially unsafe 10-in.-thick, 4-ft.-high barrier that separated bridge users from 45-mph-plus Lake Shore Drive northbound traffic, but also due to the narrow width of the path itself, which frequently caused human traffic jams and fender benders for cyclists.

In October 2000, Illinois Governor George Ryan announced a $2.1 million grant to the city of Chicago to create a new and improved bike trail on the lakefront between Belmont and Fullerton avenues to accommodate more trailer users. The Lakefront Trail Improvement at Diversey Harbor Inlet was the largest component of this project, which connects the Lakeview and Lincoln Park communities. In addition to the lakefront trail, funding for seven other projects in Chicago, Oak Park and Wilmette totaling $13.5 million was awarded by the governor. The projects were funded under three related programs administered by the Illinois Department of Transportation, which in turn, administers the Illinois Transportation Enhancement Program, a federally funded effort providing bike paths, pedestrian trails and other projects that offer transportation options other than traditional highway and mass transit. It is funded from a set-aside of federal highway funds and matched with local or state dollars.

What makes the Diversey Inlet project unusual is that the Chicago Department of Transportation handled both the architectural and structural designs and labor. According to Schlosberg, Cary Concrete worked as a “consultant and nonmanufacturing supplier, responsible for gathering estimates and drawings” for the project. The company is based in Cary, Ill., northwest of Chicago.

Two suppliers provided materials for the bridge work: Pennsylvania's Hanover Architectural Products shipped about 120 precast panels, mostly in 3-ft. dimensions to mimic limestone blocks and line underpass walls created by the bridge widening; and, Wisconsin's Advance Cast Stone fabricated 97 pier and abutment pieces, the heaviest weighing in at 16 tons. Unlike the Hanover panels, there was almost no repetition when it came to size and shape of the Advance pieces. To top off the structure, lantern-like lights were placed along the bridge. The formwork for the lanterns was done separately and delivered to Advance. “Those pieces were molded in rubber, while all the others molds for the bridge were done in wood using traditional techniques,” says Schlosberg. “The lanterns were expensive pieces since they are highly visible decorative units. They also took the longest to get made since they had to match the surrounding architecture.”

Construction on the new bridge began during the fall of 2001. Once the main bridge concept was agreed upon by CDOT and Cary Concrete, Advance delivered color samples and one was selected. No pigments were specified in the original designs and no steps were taken to guarantee color uniformity between the two suppliers. “For the panels under the bridge, the Hanover people took a look at the approved color from Advance and delivered us samples that looked similar. It worked out surprisingly well,” Schlosberg says. Design specifications did, however, stipulate that the bridge architecture did have to closely match the art deco look of the original bridge and other bridges along the Belmont-to-Fullerton trail. Schlosberg adds, “The bridge also had to be designed to support not only bike and foot traffic, but also possible emergency vehicles crossing.”

Although the improvement project had no official deadline to meet, bridge construction actually ran ahead of the architectural railing construction, so a temporary functional rail had to be built. “The temporary structures actually looked really nice,” explains Schlosberg. “We weren't embarrassed to leave those up for stretches of time while the lanterns and railings were being built.”