VCA - Tailgating

The tailgating rule detects objects which cross through a zone or over a line within quick succession of each other.
In this example, object 1 is about to cross a detection line. Another object (object 2) is following closely behind.
The tailgating detection threshold is set to 5 seconds.
That is, any object crossing the line within 5 seconds of an object having already crossed the line will trigger the object tailgating rule.

Object 2 crosses the line within 5 seconds of object 1. This triggers the tailgating filter and raises an event.