Operational Guidance for Queue Lane Switching
The other queue was moving faster. The switch was made. The original queue is now moving faster. The new queue has stopped.
OPERATIONAL GUIDE: Queue Lane Switching Prepared for: People who calculate optimal queue positions and act on the calculation.
THE SWITCH TRIGGER
The switch is triggered when an adjacent queue's movement rate exceeds the current queue's movement rate by a threshold sufficient to justify the social cost of switching.
The social cost of switching includes: the acknowledgment that you were wrong to choose the original queue, the temporary positioning in an ambiguous area between queues, and the possibility that the switch will prove to have been made at exactly the wrong moment.
THE TIMING PROBLEM
Queue movement is not predictable. A queue that has moved consistently for four minutes may stop for a completely unrelated reason: a transaction taking longer than expected, a price check, a new customer at the front. These events are not visible from the middle of the queue.
The switch is made based on historical data (how the queue has moved so far). The switch outcome depends on future data (how the queue will move after the switch). These two datasets are different datasets.
THE DOCUMENTED OUTCOMES
Outcome A: The switched queue continues to move faster. The switch was correct. The switcher arrives earlier and notes satisfaction.
Outcome B: The switched queue slows immediately after the switch. The original queue accelerates. The switcher watches their original position advance and notes mild regret.
Outcome C: Both queues move at the same rate after the switch. The switch produced no benefit and a small cost in repositioning effort.
THE RECOMMENDATION
Statistical guidance from queue behavior research suggests that switching is rarely worth it for queues shorter than twenty minutes and that the psychological cost of a failed switch exceeds the benefit of a successful one.
The switch will be made anyway. This guide is for informational purposes.
CURRENT STATUS: The switch has been made. The new queue has stopped. The original queue is moving.