What is a common challenge when coordinating multiple traffic signals?

Answer: B — Adapting to changing traffic patterns

Adapting to changing traffic patterns is indeed a common challenge when coordinating multiple traffic signals. Traffic patterns can fluctuate based on time of day, special events, road constructions, accidents, or changes in local infrastructure. This variability necessitates that traffic signal timing and coordination are regularly adjusted to improve traffic flow and minimize congestion. Effective coordination relies on continuous monitoring and analysis of traffic data to ensure that signals can respond dynamically to these changes. Failure to adapt can lead to increased delays, longer wait times at intersections, and ultimately, a less efficient transportation system. The other options, while they may represent valid concerns in traffic management, do not capture the dynamic nature of traffic flow adaptability as comprehensively as the challenge of responding to changing traffic patterns.