Better traffic flow by smarter control


In the on-going battle against traffic jams 'making better use' is one of its pillars. We can make better use of our roads if we implement technology is a smarter way. For example, by connecting all measuring and control equipment on the side of the road to make one network and subsequently use this with intelligent control systems and user-friendly software. This is what the Control Approach does.

Article from Objective #24, November 2015

Each city has one or more access roads that have to take a lot of traffic during rush hour. Depending on the amount of traffic, the traffic lights settings are adjusted; even when its completely jammed. Larger cities have a traffic center from which an operator can view live what is happening on the roads. He can adjust separate traffic lights or initiate a control program. A control program is a set of setting that, for example, regulates the duration and order of green, yellow and red light in all traffic lights at a junction. For each junction or intersection the operator has a series of separate control programs and settings available to him/her. One for morning traffic, one for evening traffic and one for the rest of the day. The choice for the correct control program is implemented in a scenario. Such a scenario is a kin of autonomous 'thing'. Loops in the road surface provide support for controlling the supply. However, the scenario does not have any awareness of the environment outside the one traffic light. What happens at a junction before or after the traffic light is not taken into account. This knowledge is in the minds of the people operating the traffic center. They known the characteristics and peculiarities of their area. They known which junctions are a problem during rush hour. And they control the scene by initiating or deactivating the right scenarios at precisely the right time. What is the right scenario? That is also in the minds of the controllers. So someone is required to keep on watching, thinking, deciding and take action when necessary.

Automatic traffic control

Those of you with a little bit of system-thinking on the brain will say: that would be perfect for automation! With that in mind, Technolution has offered to provide input for the National Traffic Management Council between Water Management and some provinces and city regions in order to think about the future of traffic management. This has resulted in the guide book of Control Approach in which parties can explain their vision on regional traffic management and take any precautions for future innovations. The word 'Control Approach' has several meanings. You can see it as a controlling technique: measuring and then taking action. But it can also concern the legislation and measures: how we wish to control the traffic in the Netherlands.

The A10 around Amsterdam

The necessity for a proper Control Approach is clearly visible in the Amsterdam region. Here Water Management, the province of Noord-Holland and the municipal of Amsterdam are working closely together. The A10 is the main road of this area. When it is gridlocked, traffic on the the surrounding provincial and municipal roads of Noord-Holland and Amsterdam are also hopelessly stuck. Water Management tries to control the A10's movement by using ramp meters. However, this resulted in problems with the corridors in Amsterdam leading towards the ramps. This was solved with coordinated widening of the network with traffic management: these three parties are all controlling their traffic management in their areas of expertise. They have established a policy about how to deal with traffic flow in these areas. This policy can be input for Control Approach.

Smart network

The technical story of Control Approach is mostly concerned with introducing network technology. Scenarios appear to be separate building blocks without any cohesion or intelligence. Control Approach brings all the equipment together and allows it to communicate and collaborate. This is how a large network is created. But in order to make the system communicate, intelligence is required. The system needs to know what to do. This knowledge is still in the minds of the traffic experts and operators, but can be implemented in the Control Approach system.

With Control Approach: always the right settings

When a traffic center has a Control Approach, the system will take over part of the control and thinking that was previously done by a person. It will initiate the right scenarios on its own and implement them real-time in a situation. It assess through the loops, radars and traveling time cameras the situation of the traffic network. The system knows where the equipment is, where the junctions are and how they all go together.

The most important aspect for the system is: to known what to do and why. What is the final goal? The knowledge comes from the municipal policy. The traffic controller feeds the system a bunch of policy regulations. "Between A and B, we want a maximum traveling distance of 10 minutes. Road C must remain accessible. In case of an incident, we want to divert traffic on so-and-so road."

Depending on the actual measured situation in reference to the policy regulations, the system decides where on the road network the flow needs to be improved (for example, more green light in a certain direction), restricted (for example, longer red lights) or redirected (for example a suggestion on a text board). This control is gradually implemented. So it also recognizes: when I improve traffic flow on this junction, I also have to adjust the adjacent junctions so the area remains in balance. The system translates the municipal policy regulations to control technique with assignments for each junction.

Steering with policy regulations

With the Control Approach policy-makers and traffic experts can easily design and adjust a traffic control system. The vocabulary and the controls match their thinking processes and the rift between policy and reality comes that much smaller. The user understands that he/she puts in and the system shows the results: did you get the desired traffic flow between A and B and the perfect balance in this controlled area?

Also, Control Approach makes work a lot easier in the workplace. In the former situation, the operator had to choose a scenario with standard settings. But traffic is never constant and therefore settings cannot always be truly perfect. Control Approach uses mini-scenarios and real-time data to make immediate adjustments to these changes and automatically determine the correct setting for the scenario. This way, you can use your network more efficiently with all the equipment available to you with as final result: better use of the road and better accessibility of the city. The number of "vehicle loss hours" will significantly decrease thanks to Control Approach.

The production, and especially the maintenance and management, of separate scenarios is quite labor intensive. Water Management and the provinces have a couple of hundred standard scenarios. After a small change in a road or junction, they will have to adjust dozens of scenarios. Control Approach only needs to known the road's change and will implement any necessary adjustments. The establishing and maintaining of scenarios has became that much simpeler.


Control Approach is a logical step in the evolution of mobility. Automating the manual work in scenarios and adding knowledge to the system. The future is in more data, for example, the car as sensor/actuator and smarter control systems. This is already happening in project Autopilot. This project has the assembled (mini)scenarios that are crucial for Control Approach and are fully automated. The system can automatically decide what is the best choice from all possibilities that it has to manage traffic within the standard policy regulations.


  • Paul van Koningsbruggen
  • Director Mobility
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