What is a potential consequence of not reviewing the monitor cards regularly?

The potential consequence of not reviewing the monitor cards regularly relates directly to the operation of the traffic signals. Monitor cards are essential records that provide data on the functioning of traffic signals, including any malfunctions, irregularities, or trends in signal performance. If these cards are neglected, it may lead to undetected issues that could cause incorrect signal operations. For example, critical faults might not be addressed in a timely manner, resulting in signals that do not function as intended. This can lead to safety hazards, increased traffic congestion, or accidents as drivers may encounter signals that are not properly synchronized or timing incorrectly.

In contrast, the other outcomes listed do not directly correlate with the failure to review monitor cards. Increased traffic flow and enhanced safety would typically improve with well-functioning signals, influenced by regular monitoring and corrective actions based on insights drawn from those monitor cards. Higher maintenance costs might arise over time as a result of neglect, but the immediate and most significant risk is indeed the incorrect operation of signals, emphasizing the critical nature of regular review and maintenance practices.