DuSable Lake Shore Drive Bridge Will Close 10 P.M. to 5 A.M. Nightly Through Sept. 16 for Trimming and Electrical Testing

The DuSable Lake Shore Drive bridge will close every night from 10 p.m. to 5 a.m. through Sept. 16 so crews can trim the center break and run electrical tests, according to an email from Ald. Brian Hopkins (2nd).

The overnight work covers a stretch of the roadway that carries about 102,000 vehicles a day, according to Illinois Department of Transportation figures. During the closure window, drivers will be rerouted onto East Wacker Drive, North Columbus Drive and East Illinois Street. CTA bus routes #134, #135 and #136 will follow the same detour while the bridge is shut down.

The testing comes a little more than a week after the bridge got stuck open for more than four hours, snarling traffic across downtown for most of a workday. The Chicago Department of Transportation said that malfunction happened because extreme heat caused the bridge's steel components to expand, jamming the mechanism that normally lets the span close. It is not clear whether the nightly tests are connected to that malfunction or were scheduled independently of it.

The stuck-bridge incident drew scrutiny partly because of the circumstances that led to it. The bridge had been raised to let a cruise boat pass through the waterway during the same stretch of extreme heat, and commuters questioned why the city allowed that opening given the risk the heat posed to the bridge's operation. The transportation department responded that it is "federally required to operate movable bridges for waterway navigation upon a properly submitted request," and it has declined to answer further questions about the decision to raise the bridge that day.

The bridge also carries a flagged inspection history. A 2024 inspection rated the structure as structurally deficient, a classification that reflects wear on components rather than an immediate safety threat. That rating does not mean the bridge is unsafe to use, though the recent malfunction renewed attention on its maintenance record.

The nightly closures give the transportation department a window to work on the bridge without shutting it down during peak travel hours, when the corridor handles heavy commuter traffic and event trips to Navy Pier and the Museum Campus. Running the work between 10 p.m. and 5 a.m. keeps the bridge open through rush hour and most evening activity, though it still forces overnight drivers and the three CTA routes onto surface streets for more than a week.

The closures are scheduled to end after Sept. 16, when the bridge is expected to resume normal overnight operation. The transportation department has not said whether additional testing or repairs will follow, and it has not released a timeline for addressing the 2024 structural deficiency finding beyond the current round of trimming and electrical checks.