Technical Documentation
Version 2023.3 (EN)

Set-up Queue Length Detection

How to get insights on traffic congestions in terms of data generation, camera set up and Analytics options.
Next to the traffic frequency at given locations, you are wondering about the length of a queue when traffic congestion is given. In combination with the speed of the detected vehicle, you can get proper insights into the length and speed of the current queue.

What data can be generated?

For this use case, SWARM software is providing you with the most relevant traffic insights - The counts of vehicles including the classification of the SWARM main classes can be covered. On top, you have the opportunity to add a second counting line, calibrate the distance in between and estimate the speed of the vehicles passing both lines. By combining this with different Regions of Interest (RoI) you can retrieve the needed insights into traffic congestion.
For traffic frequency, all SWARM main classes can be generated. Depending on the camera settings, we can detect present vehicles up to 70 m.

What needs to be considered for a successful analysis?

Possible cameras for this use case

Camera Set-up
How to configure
How to get the data?
Find detailed information about camera requirements/settings as well as camera positioning in the table below.
Set up parameters
Pixels Per Meter is a measurement used to define the amount of potential image detail that a camera offers at a given distance.
> 60 PPM
Using the camera parameters defined below ensures to achieve the minimum required PPM value)
Camera video resolution
1280×720 pixel
Camera video protocol/codec
Camera Focal Length
min. 2.8 mm variofocal lense*
Camera mounting - distance to object center
5–70 meters*
Camera mounting height
3–8 meters
Camera mounting - vertical angle to the object
Note: setting the correct distance to vehicle and camera mounting height should result in the correct vertical angle to the vehicle
Camera mounting - horizontal angle to the object
0° - 90°
*The higher the distance of the objects to the camera, the higher the focal length, the higher the dead zone. In order to achieve the needed PPM for the detection of objects (30 PPM, please consider the following illustration and table:
3 Object Distances and Focal Lenghts
Object Distance
Focal Length
Dead Zone
2,8 mm
2,8 mm
5 mm
5 m
7 mm
>8 m
Possible cameras for this use case
The configuration of the solution can be managed centrally in SWARM Control Center. Below, you can see how the standard is configured for optimal results.
In order to start your configuration, take care that you have configured your camera accordingly.

Configuration settings

Configuration option
Counting Line & RoIs
Raw Tracks

What should be configured?

In order to receive the counting data including speed as well as the RoIs occupancy, a Counting Line and several RoIs need to be configured as event triggers. Depending on the specific use case and object distance, several triggers might need to be combined.

How to place the event triggers?

In order to receive information on how fast vehicles are driving and how many objects are currently present in a specific region, you need to configure counting lines with speed estimation and generic RoIs.
Combine CL, Speed and RoI for Queue Length Detection
You can choose the direction IN/OUT as you want in order to retrieve the data as needed and give a custom name to that direction.

Visualize data

You can visualize data via Data Analytics in different widgets.


In our Traffic Scenario section, you can find more details about the possible Widgets to be created in the Traffic Scenario Dashboards for Speed Events and combined trigger.
If you need your data for further local analysis, you have the option to export the data of any created widget as .csv file for further processing in Excel.
csv. export
If you would like to integrate the data in your IT environment, you can use the API. In Data Analytics, you will find a description of the Request to use for retrieving the data of each widget.

Environment specification

Object velocity
< 130 km/h
Daytime/Well illuminated/Night vision
Expected Accuracy (Counting+Classification)
(when all environmental, hardware, and camera requirements are met)
Counting >95% (vehicles, bicycles) Classification of main classes: >95% Classification of subclasses: >85%

Hardware Specifications

Supported Products
VPX, P401, P101/OP101, P100/OP100
Frames Per Second