The Chicago Department of Transportation (CDOT) is undertaking a yearlong project to reconstruct the Halsted Street Bridge over the Chicago River’s North Branch Canal. Long plagued by traffic congestion and dangerous pedestrian conditions, the two-lane crossing will be rebuilt to accommodate two lanes in each direction and dedicated bicycle lanes and sidewalks.

Built in 1909, the existing movable bridge hasn’t been raised in more than 25 years because large boats no longer navigate the canal. “The bridge is the earlier type of bascule bridge,” said Soliman Khudeira, project director for CDOT’s Division of Engineering, referring to its pivoting design. “It is what we classify as ‘functionally obsolete’ because it carries only one lane in each direction, and additional lanes in each direction are justified because of the traffic.”

The bridge has been closed since last month, when construction began on the new span, a simply supported tied-arch design that will widen the bridge’s deck from 60 to 80 feet, replacing the movable steel grating and truss with a new structural slab and built-up steel box-arch ribs, rib bracings, and structural strands. New reinforcement concrete abutments on steel piles will be built in the canal to support the main span.

“The advantage of a tied-arch bridge is that it allows the girders below the deck to be shallower,” said Khudeira. “In addition, any suspension or cable-stayed bridges add substantially to the aesthetic of the area.”

Designed by Chicago-based architecture firm Muller+Muller and infrastructure and engineering firm H.W. Lochner, the new crossing will dramatically improve conditions for bicyclists, who in the past have used sidewalks or shared driving space with cars. Painted bike lanes will connect with existing lanes to the north and south of the bridge, and sidewalks will be separated by a railing. The design looks ahead to the time when Chicago’s Riverwalk will continue to this portion of the canal, with two 34-foot-wide pedestrian tunnels on either side of the bridge. Though these will be closed upon completion, the city expects they will become part of a newly landscaped area in the coming years.

While similar projects have diverted traffic over a temporary structure parallel to the existing span, Halsted Bridge engineers were limited by Com Ed towers on one side and a FedEx center on the other. The construction will close Halsted from Division to Hooker Street and cars and trucks will be detoured—commercial vehicles to the west and all other traffic to the east—for the project’s duration, a plan that is already causing jams.

Nevertheless, the $27 million project points to progress on the Chicago riverfront. Khudeira’s office is already working on two future Division Street bridges that will complement the Halsted Street Bridge design, not to mention its function. “We think the area will improve dramatically, aesthetically,” he said.