Measure waiting time in a queue

In front of a counter, a ticket machine or a lift, the time each person spends in the waiting area is their waiting time. A zone measures it for everyone. A rule can also record each wait that runs longer than you accept.

The practice uses the Floor zone from guide 09 as the waiting area. For a real queue, draw the zone over the floor where people stand in line.

Step 1. Create a separate experiment

A new experiment keeps the rule apart from the occupancy study of guide 09. Both use the same scene.

1. Open Experiments and click New experiment.
2. Set Name to Queue times, pick the Corridor camera, keep Person and click Create experiment.

Step 2. Add a rule for long waits

1. In the Rules panel of the experiment page, click Add rule.
2. In the mode list next to the rule name, choose Remains in zone for….
3. Set the rule like this:
   • Rule name: Long wait.
   • WHEN: Person.
   • ENTERS: Floor.
   • AND REMAINS FOR: more than 5 seconds.
   • CREATE EVENT: Long wait.
   • ACTIONS: keep Count and Record event ticked.
4. Click Save.

Step 3. Run it

1. Click Start at the top of the experiment page.
2. When the run has finished, click Results in its row under Runs.

Step 4. Read the waiting times

In Zones (occupancy and dwell), the visits of Floor are the waits:

The median is often the better summary for a queue, because one very long wait pulls the mean up.

The Events by type list counts the Dwell events of the rule. With the recommended detector the sample has 3: two people at about 00:20 and one at about 00:33. Each is recorded at the moment the person has been in the area for 5 seconds, while they are still in view. Someone who walks out of the picture stops adding waiting time at the moment they were last seen.

Rules or built-in flags

The zone inspector has Flag visits longer than, which records a Dwell exceeded event without a rule. Use it for a quick flag on one zone. Use a rule when you want any of these:

• Your own name for the event, shown in counters and exports.
• Fewer classes than the zone counts, for example only Person in a zone that also counts cars.
• A webhook that tells another system at once. See guide 20.

Export the waits

1. Open Data.
2. Set Experiment to Queue times and Event type to Zone exit.
3. Each row is one completed wait. Duration is its length in seconds.
4. Click CSV to download the rows for a spreadsheet.

Next

Guide 11 follows people from an entrance to one of several exits.