| Interval starts | Arrivals | Lanes open | Per lane / 15 min |
|---|
Reading the results
- First queue is the first interval that ends with people still waiting. Before that, every arrival was processed within the interval they arrived in.
- Peak queue is the largest end-of-interval backlog and when it happens. That is the moment your entrance looks worst and when crowd pressure, frustration and queue-jumping start.
- At the end is how many are still waiting after your last interval. If it is not zero, the tool projects a clearance time by assuming the last interval's capacity continues and no one else arrives. That projection is not part of your entered data; treat it as a sanity check, not a plan.
- Plan B opens extra lanes from a chosen time. Opening a lane before the backlog starts prevents it; opening one afterwards only shortens it. Try moving the start time earlier and watch the peak.
Worked example
Doors at 18:00 with two lanes each processing 30 people per 15 minutes, so 60 per interval. Arrivals climb from 40 to a peak of 220 at 18:45. The queue first appears at the end of the 18:15 slot (90 arrived, 60 processed, 30 waiting), peaks after the 18:45 slot and takes until well after 19:45 to clear. Open a third lane from 18:15 and the peak roughly halves; open it from 18:00 and the first backlog disappears, because 90 arrivals meet 90 capacity.
Getting better numbers
- Arrivals come from ticket scans at previous events, the box office's expectation and the start time. Most audiences bunch in the 45 minutes before a start time.
- Throughput per lane depends on the search level. A bag search with a wand is slower than a ticket scan alone. Time ten people through one lane and scale up.
- Lanes are limited by staff, equipment and width, and by the search requirement in the event's risk assessment.
Queue management, crowd dynamics and the duties of event stewards are part of the Security Guard course, and the Door Supervisor course covers searching and entry procedures.
FAQ
How do I calculate how long a queue will take to clear?
Divide the people waiting by the number you can process per interval, then multiply by the interval length. If 150 are waiting and you process 60 per 15 minutes, clearing takes about three intervals, or 45 minutes, provided nobody else arrives.
Why does the queue not clear even though total capacity exceeds total arrivals?
Because capacity is per interval. Sixty spare places at 18:00 cannot process people who arrive at 18:45. Only capacity available at or after the arrival time counts.
How many people per minute can a search lane process?
It varies with the search level. Ticket scan only can exceed four a minute; a bag search with a wand is often under two. Measure your own lanes and enter that number.