Although construction on the Central Street bridge over the North Shore Channel is not scheduled to begin until 2019, analyses and tests have been conducted, and traffic plans are in place for the months-long project to replace the century-old bridge.
The new bridge will be 7 feet wider, to accommodate a 10-foot sidewalk and parking on the south side, as well as a dedicated bike lane. “It will be a complete street,” City Engineer Sat Nagar said to a small but interested group of residents at a meeting in the Civic Center’s Parasol Room on May 25.
Infrared/thermal-imaging determined that the surface of the bridge was so deteriorated as to warrant full replacement, said Paul Schneider of Stanley Consultants, the company the City has hired to manage the first phase of the project.
“We saw the alligator cracks on the asphalt and saw the asphalt was deteriorating. We figured that 40% of the deck would have to be rehabilitated. The Illinois Department of Transportation (IDOT) recommended replacing only 30%,” Mr. Schneider said. “The bridge is safe to drive on,” he said, but concerns remain about the long-term safety of the bridge, so Stanley recommended replacing the entire bridge.
A single span will replace the current three spans. With fewer joints exposed to the elements, and with the abutments placed on land rather than in the water, the new bridge could age as well as the present one, lasting 100 years, Mr. Nagar said. It will also be easier to maintain, Mr. Schneider said.
A slope of grass to the south and west of the bridge will serve as the construction staging area. At each end of the bridge, the surface of Central Street will be smoothed to mesh with the new bridge, Mr. Schneider said.
The project will extend from Bryant to Girard streets, a slightly greater distance than the span of the new bridge. Three jurisdictions in addition to the City are involved in this physically small project. The City owns the bridge, and the abutments and staging for the new bridge will be on property owned by the Metropolitan Water Reclamation District. The City will have to negotiate with MWRD to purchase the small amount of land for a wider bridge and perhaps lease rather than buy the staging area. Since Central Street is a State highway, the Illinois Department of Transportation is involved.
The fact that federal funds will pay for the majority of the cost involves the Federal Highway Administration as well.
Beginning in 2019, the south half of the bridge will be replaced. One lane of traffic will be open in each direction, so emergency vehicles from the fire station and the hospital will still be able to serve residents; football fans will have access to Ryan Field; and CTA commuters, golfers, and residents will be able to continue their customary traversings. In 2020, the north half will be replaced – with, similarly, one lane of traffic in each direction – and then the old bridge will be demolished.
The Life of the Central Street Bridge
In 1908 when MWRD widened the canal, it built bridges at Central, Lincoln, and Isabella streets and almost immediately turned them over to the City of Evanston. In 2014, during the City’s biennial bridge inspection, crews found severe deterioration in the Central Street bridge, among other places, in the core in the concrete supports. The safe load limit was restricted to 15 tons.
The following year, crews placed steel collars around the concrete columns, and the weight restrictions were removed in November. The City hired Stanley Consultants to assess the need for repairs, and requested IDOT funding. The City will have to pay only 20% of the expected $5.5 million cost.
Although the construction will not begin for another 19 or 20 months, some residents were concerned about collateral damage from the project. In answer to one resident’s question, Mr. Schneider said the crews would hose down the area regularly to minimize the dust.
Mr. Schneider also said crews would work with the City arborist regarding the removal and replanting of trees in the staging area. “We’ll work with [City Environment Bureau Chief] Paul D’Agostino to check about canopies and root structure; we’ll put [protective] boards around trees,” he said. He also said that heavy equipment would be moved and stored in the staging area.
“For every tree we take out, we plant three trees,” Mr. Nagar said.
Lara Biggs, Engineering and Capital Planning Bureau Chief for the City, said, “This project, like any project, can be intrusive, but we will try to minimize it.”