Green on demand pilot project in the Netherlands


Smart overhead cameras supersede conventional detector loops embedded in the road surface which are costly to replace.

The Challenge



Replace end-of-life detection loops with AI-powered cameras to control traffic lights on demand

Parquery replaces sensors to detect road users

Noted not only for its cycling culture, the Netherlands are often referred to as a pioneer in multimodal transport, traffic innovations, and engineering. 

Most Dutch traffic lights are actuated, i.e. demand-controlled, to accommodate fluctuations in traffic flow. Sensors detect road users as they approach an intersection or at the traffic lights. When the detector registers a road user, it automatically alerts a control mechanism that influences the times of the signals - red and green - e.g., by extending green phases or switching them faster. 

Actuated signals that adapt to changing traffic patterns thus reduce travel delays and are, therefore, more efficient for everyone, including motorists, cyclists, and public transport. They increase the capacity of an intersection.

Parquery helps reduce traffic congestion in cities by actuating green lights automatically

From this...

Parquery helps reduce traffic jams in cities by actuating green lights automatically

to that!

Conventional means are not satisfactory


Inductive loops are the conventional means for detecting road users and actuating traffic signals. They are wires buried in the road surface that register a vehicle’s presence through the change in the magnetic field.

Their drawback, however, is that they are inconvenient, complicated, time-consuming, and costly to install and repair. Installing and repairing requires road construction work and disruption of traffic.

They have also proven unreliable, notably for smaller vehicles and motorbikes, and often fail for user groups like pedestrians and cyclists.

Trenches have to be cut into the asphalt for the inductive loops, and repairing them is costly

Trenches have to be cut into the asphalt for the inductive loops. Repairs and replacements are costly, inconvenient, and demanding.

Parquery detects near-accidents or if vehicles run red lights

Failure to detect vehicles can result in long waits at traffic lights. At busy crossings, incoming traffic from behind can solve this problem. After a while, however, motorists tend to run a red light, especially if there is no apparent reason for it, leading to potentially dangerous situations.

That’s why the Dutch traffic industry has been looking for reliable and accurate alternatives for decades.


The Solution

Parquery detects road users approaching and waiting at traffic lights in video streams



Detect road users approaching and waiting at traffic lights in video streams with Parquery’s Artificial intelligence (AI).


Building on a successful project on camera-based incident detection on behalf of the province of Utrecht, The Netherlands, the trio of Vialis, Hyrde, and Parquery took on the challenge of replacing induction loops with cameras. The cameras installed for the incident detection project at a busy intersection then additionally served to detect road users - vehicles, motorbikes, and bicycles.

Parquery provides traffic analysis results to Provincie Utrecht

The goal of the project was to determine whether road users detection in video streams can replace inductive loops, i.e. is at least as reliable. Accuracy means that as few approaching or waiting vehicles as possible are missed and forced to wait. 

[...] the results were astonishing and the so-called matching rate was high - even without prior adjustments and tuning. The latter is particularly encouraging!

Willem Hartman, Director Digiways, Vialis


Incident detection and traffic analytics with Parquery

Find out more  Project in Utrecht

Project setup


Ideally, a camera is mounted above the center lane to ensure the clearest possible view and to observe all lanes. If the camera is mounted to one side, larger vehicles in the foreground may hide smaller vehicles in the adjoining lane. 

The video is then analyzed on a small, powerful computer mounted near the camera on site (edge computing), thus avoiding transferring the video over a network to a remote server. Parquery’s video analysis then detects approaching and waiting vehicles in the live video stream. The system is based on Artificial Intelligence (AI), a learning algorithm which allows it to adapt to new scenes and road users

Parquery detects approaching and waiting vehicles in the live video stream

Unlike sensors embedded in the road, cameras can cover wide areas and see farther. This has two positive implications: 

  • One camera can monitor multiple lanes; their number depends on the camera’s mounting height and field of view. 
  • In addition, vehicles approaching the traffic light can be detected while still afar, and the green phase extended accordingly. 

In contrast, several loops must be installed in succession at increasing distances from the traffic light for each lane to achieve the same with induction loops.  


Contact us  More about this solution 


The advantages in brief


  • Added value for existing traffic surveillance cameras
  • Considerable savings in total cost of ownership
  • Less expensive, simpler installation with no road work or traffic disruptions as with inductive loops or magnetic ground sensors
  • Easier maintenance without affecting traffic flow
  • Early detection of road users approaching an intersection, resulting in smoother traffic flow as green phases can be dynamically extended or shortened even before the vehicle comes to a stop
  • Distinguish different types of road users 


Compare technologies

cameras powered with Parquery's AI have many benefits over induction loops - e.g. easy installation

Installing, repairing, or replacing a camera can be combined with traffic light maintenance and does not cause traffic disruptions

Get in touch to start controlling your traffic signals in real-time with AI


Contact us

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