The Madison Street Bridge over the Chicago River will be closed for testing Thursday ahead of the spring boating season.
The bridge will be closed from 9:30 a.m. until 3:30 p.m., according to a statement from the Chicago Department of Transportation.
Eastbound traffic on Madison will be rerouted via Wacker, Randolph and Clinton, CDOT said.
The testing is part of CDOT’s preparation for spring boat season. The department started testing bridges along the river length last month to ensure that they’re ready for the weekly bridge lifts that start in the spring.
Every spring and fall, workers raise the movable bridges along the Main and South branches of the river on Saturdays and Wednesdays to accommodate recreational boats traveling to and from the storage yards.
The process is called a “boat run,” and it involves raising all 27 bridges between Ashland and Lake Shore Drive sequentially, usually one at a time. Each bridge lift takes an average of 8-12 minutes.