What best describes a fixed-time signal?

• A. It uses detectors to adjust cycles
• B. It responds to pedestrian calls to adjust timing
• C. It changes timing randomly
• D. It cycles through phases with predetermined, fixed offsets regardless of current conditions

Answer: (D)

Fixed-time signals run on a pre-set schedule. The cycle length and the time allocated to each phase are fixed, and the start times for each phase within the cycle are predetermined, giving fixed offsets. Because nothing during a cycle depends on current traffic or pedestrian activity, the sequence remains the same every cycle. This combination—predetermined phase durations and offsets regardless of conditions—best describes a fixed-time signal.