Contractors ride along the Highland Park Bridge where they are installing warning signs near the Allegheny River Lock and Dam 2 for the U.S. Army Corps of Engineers Pittsburgh District in Pittsburgh, June 14, 2023. The Pittsburgh District installed the warning signs to protect boaters from getting too close to the fixed-crest dam, which can be deadly and is invisible from upstream because it is submerged underwater. The district designed the warning signs especially for recreational boaters, making them visible from approximately a half-mile away during clear days. The signs have a reflective coating, making them visible also at night. In addition to the new signs, the Pittsburgh District installs safety buoys at the beginning of each summer and removes them at the end of the recreational season. The district coordinated directly with the Pennsylvania Department of Transportation to receive special permission to install the signs on the bridge. (U.S. Army Corps of Engineers Pittsburgh District photo by Michel Sauret)