The shutdown of the Wells Street Bridge has the impact of a blocked artery, straining the circulation of much of the CTA rail system.
The lower tier of the 91-year-old bridge was closed to vehicles and pedestrians in November for repairs, and now it's CTA riders' turn.
Even though only Brown Line and Purple Line/Evanston Express trains normally travel across the Wells bridge connecting the Loop elevated structure to tracks north of the Chicago River, service on six of the eight CTA rail lines is being affected by bridge and track work continuing through the week, transit officials said.
Weekday rush hours are expected to pose the biggest challenge to the transit agency and its customers. Brown Line trains will operate much less frequently during most of the day — running every 10 to 12 minutes, officials said. And Evanston Express service is canceled until March 11. Purple Line local service will continue to operate between Howard Street in Chicago and Linden Avenue in Wilmette.
On weekends, Green, Pink and Orange Line trains will terminate their runs at certain stations in the downtown area, officials said. A weekend free shuttle bus will operate to link the Chicago/Franklin, Merchandise Mart, Clark/Lake, Washington/Wells and Clinton/Lake stations, officials said.
Riders are being told to plan for longer, slower commutes starting Monday on trains that will be more crowded than usual. The frequency of trains on the Brown Line is being reduced because of the need to operate more trains than usual on the Red Line tracks, including in the State Street subway, officials said.
"Experience has taught me to become a little nervous any time the CTA changes service," Rick Gordon, 41, a Brown Line rider who commutes between the Western station and the Washington/Wells stop in the Loop, said Friday morning after getting off the train downtown.
Gordon, an investment counselor, said he still plans to ride the Brown Line on Monday. But because he won't be able to ride across the Wells bridge to his normal stop, he will instead take advantage of the free CTA shuttle bus that will operate between the Chicago Avenue station and the Loop "L," stopping at the Merchandise Mart, the Clark/Lake and Washington/Wells stations.
During rush hours, two of every three southbound Brown Line trains will travel through the Red Line subway tunnel, making all stops to the Roosevelt station, officials said. They will then head north through the subway and up to Fullerton Avenue, then will continue making all Brown Line stops to the Kimball Avenue terminal, officials said.
One of every three Brown Line trains will remain on the regular Brown Line route south of Fullerton but will make the last stop at the Merchandise Mart station, near the north end of the Wells bridge.
Extra service will be provided on the Red Line, in part to accommodate heavier passenger loading caused by the suspension of all Purple Line service south of Howard through the week, officials said. Commuters who normally ride the Purple Line/Evanston Express service might consider budgeting up to an extra hour travel time if they will ride the all-stop Red Line to downtown.
Also, the transit agency will introduce free shuttle trains that circle the Loop and alternative bus service to provide options for the thousands of riders affected over the roughly nine-day bridge closing, which began Friday night.
CTA officials predicted that the commutes of many rail customers will be only several minutes to 15 minutes longer than normal travel times during the service interruptions. But in light of the unpredictability of CTA service even under normal cases, allowing extra time would help commuters ensure they arrive at their destinations on time.
"We urge customers to think about their options because this will not be a typical commute for most Brown and Purple Line commuters," CTA spokesman Brian Steele said, adding that delays are likely on other lines too because of expected ridership shifts.
With some commuters taking Monday off for the Casimir Pulaski Day holiday, the first full test of the CTA's alternative service plan will likely be on Tuesday.
The service disruptions will last until completion of the Wells bridge replacement project, upgrades to the busy downtown rail junction at Lake and Wells streets, and track replacement around the curves at Hubbard and Kinzie streets. Regular CTA service resumes in time for the morning rush period on March 11, following the first phase of bridge reconstruction, officials said.
A second closing of the Wells bridge will occur April 26 through May 5, when the $41.2 million overhaul project is scheduled to be completed, the Chicago Department of Transportation said.
The Wells bridge's trusses, steel framing, railings, bridge houses, major structural parts and mechanical and electrical parts are being replaced, but the original 1920s-era appearance of the double-deck bridge will be maintained, CDOT officials said.
Full details on the CTA service changes are available at transitchicago.com/wellsbridge.
jhilkevitch@tribune.com Twitter @jhilkevitch
