Identify one challenge faced by switchmen during foggy conditions.

Reduced visibility during foggy conditions is a significant challenge for switchmen because it directly impacts their ability to see important signals and track conditions clearly. In foggy weather, the line of sight can be severely diminished, causing difficulties in identifying track switches, signals that indicate train movements, and other critical safety markers. This impairment not only increases the risk of operational errors but also complicates the switchman's ability to communicate with fellow crew members and correctly assess the environment around them. As a result, this challenge requires switchmen to rely more heavily on their training and established protocols to ensure safety despite the reduced visibility.