Modeling queue counters
Queue lengths can be determined with queue counters at any point in the Vissim network and evaluated for any time interval. This is facilitated by stop lines of signalized intersections on links and connectors. The following values are output (Showing results of queue counters in lists):
- Maximum queue length
- Average queue length
- Number of queue stops
In 2D mode, you can display queue lengths at each queue counter or at queue counters in nodes (List of graphic parameters for network objects).
Queue definition with queue conditions
Queues are measured from the upstream position of the queue counter up to the last vehicle for which the queue conditions apply. You define the queue conditions when configuring the evaluation of the queue counters. To evaluate queue lengths, you can take the adjacent lanes of previous links into account (Showing results of queue counters in lists).
Queue with multiple ends
If a queue has multiple ends, queue lengths are recorded at every time step on all arms of the queue which are upstream to the queue counter. The queue counter then returns the average queue length of the arm, for which the longest queue was measured. At this time step
Length of a queue
The length of a queue is detected as long as the queue has been eliminated completely, even if vehicles have resumed driving between the queue counter and the queue end and no longer meet the queue condition. The queue length is measured up to the last vehicle remaining in the queue that meets the condition until the queue condition is no longer met by any of the vehicles.
Queue lengths are output in terms of units of length, not in terms of number of vehicles.
Queues are always tracked up to their original end, even if the first vehicles are no longer in queue.
The maximum queue length is as long as the distance to the next queue counter upstream or as long as specified in the queue definition for the attribute Max. length. For a queue counter that is automatically generated by Vissimfor node evaluation, the maximum queue length is the distance to the next queue counter, upstream in the node.
If upstream of the queue counter’s position several connectors lead to a link, the queue counter detects congestion along all of these connectors and outputs the length of the longest of these traffic jams.
