CTA Brown Line and Purple Line/Evanston Express trains will still operate over the bridge, except during two separate nine-day periods next spring, in early March and late April, according to the CTA and the Chicago Department of Transportation.
The rail stoppages will coincide with a CTA project to rebuild the Loop elevated Tower 18 junction at Lake and Wells streets, officials said.
The Wells Street bridge, which opened in 1922, has reached the end of its useful life and requires a complete rehabilitation, according to CDOT.
The bridge's railings, bridge houses, major structural components and mechanical and electrical components will be replaced, preserving the original appearance of the span, officials said. Crews will replace the trusses and all of the steel framing for the lower-level road and upper-level rail structure.
Work is scheduled for completion in November 2013, officials said. The contractor on the project is Walsh/II in One (JV).
Starting Monday, southbound vehicle and pedestrian traffic on Wells will be rerouted to the bridges at LaSalle and Clark streets. Southbound bicycle traffic can cross the river on the Clark Street bridge.
CTA No. 11 Lincoln/Sedgwick and No. 125 Water Tower Express buses will be rerouted via Kinzie and LaSalle streets and Wacker Drive back to Wells, CDOT said.
The Tower 18 work at Lake and Wells was originally scheduled as part of the ongoing Loop track renewal project. But by performing the work while CDOT completes the Wells bridge repairs, CTA will reduce the duration of the work by eight days, officials said. Combining the work will also save $500,000 in construction coordination costs, officials said.
During the two nine-day closures of the Wells rail bridge, CTA will provide alternative bus and rail service, officials said. On weekdays, Brown Line trains will alternate between terminating at Merchandise Mart or continuing into the Loop through the State Street subway. Shuttle buses will operate from the Mart as well as special shuttle service on the Loop elevated track.
The Tower 18 junction handles almost 700 trains on an average weekday and nearly 500 trains on an average weekend. Five of the CTA's eight rail lines pass through the junction.