Extreme heat is paralyzing Chicago’s moveable bridges

Severe heat in Chicago led to two moveable bridges getting stuck in their raised positions for hours on Sept. 2. The DuSable Lake Shore Drive bridge was stuck for more than four hours, and the Torrence Avenue Bridge was unmoveable for over an hour, causing disruptions and traffic jams for city residents.  

Wednesday was Chicago’s second day under a heat advisory, writes Amy Yee for the Chicago Sun-Times. When lowered, moveable bridges are protected from extreme heat due to the river cooling the air. However, if the bridges are raised, the heat can cause the metal to expand and jam the bridge's mechanisms, preventing it from lowering.

“As a city with so many older movable bridges and extreme hot and cold weather, Chicago is vulnerable to stuck bridges,” the Sun-Times reports. “Chicago also has the most moveable bridges of any city in the U.S., making it potentially more vulnerable to heat-related closures.”