Expert interview Verkrehsmanagement - road with vehicles

Eco-sensitive traffic management

Interview with Frank Felten and Matthew Fullerton

Transport has a key role to play in efforts to improve air quality. In our interview with Frank Felten, Chief Product Officer at Hawa Dawa, and Matt Fullerton, Chief Technical Officer for Software & Hardware at Hawa Dawa, we shed light on this relation. What approaches are there? What is critical? What hurdles need to be overcome?

Transport and the environment are often mentioned in the same breath. Where does that come from?


Unlike air pollutants, traffic is immediately «visible». Thus it is perceived directly. Today, many citizens equate traffic jams with a loss of time and an environmental problem. The connection between «air quality and traffic» has reached society (and politics).

The environmental impact of traffic in urban areas is particularly significant. Here, not only the volume of traffic is high. In addition, the building structure often leads to bottlenecks and also impedes air exchange. This will become even worse in the future due to increasing urbanisation.

Even if electric drives certainly help to reduce nitrogen dioxide pollution, the higher weight of these vehicles leads to more abrasion from the road surface tyres, which in turn increases the fine dust pollution.


According to the Federal Environment Agency (UBA), about 40 % of nitrogen dioxide pollution, and sometimes up to 60 % in heavily polluted cities, can be attributed to road traffic. We are familiar with the discussion from the media, which often refer this to some of the «worst hotspots» in Germany: Stuttgart Neckartor, Munich Landshuter Allee, Stresemannstraße in Hamburg, Theodor-Heuß-Allee in Kiel.

In the case of particulate matter, the share attributable to traffic is lower (according to the UBA, less than 30 % on average) – here, the lion’s share comes from production processes, and private households (heating) also have a significant share.

Particulate matter in traffic is the result of braking and tyre wear. 

Nitrogen dioxide is known to be the product of conventional combustion engines.  

Of course, technological progress in recent years has led to less nitrogen dioxide being emitted «per horsepower». Electrification based on green electricity at least helps with nitrogen oxides. But the steady growth in vehicles, kilometres driven, and congestion kilometres generated has more than compensated for these achievements: The transport sector’s record on climate gases and air pollutants has not improved since 1990.

What does «eco-sensitive traffic management» mean?


Well, I learned in my studies that traffic is «planned» on the one hand and «managed» on the other: 

Transport planners are more concerned with medium-term issues, often with infrastructure: how can a (construction/residential/industrial) area be developed in terms of transport, where can roads, railways and paths be built, and how many, etc. – in planning, it’s mostly about the question of how to record the demand for transport services and mobility and then create a corresponding transport offer.

Traffic management is much more short-term oriented. Here, the transport offer is essentially available, and the task is to schedule all transport users and modes of transport as optimally as possible in the network of possibilities. What is new and «environmentally sensitive» is that optimisation is no longer understood solely as an improvement in travel times or throughput in the network, but at the same time, aims to reduce or at least better distribute negative environmental impacts (air pollutants, CO2, noise, etc.).


Regarding eco-sensitivity, traffic management must not be equated with optimising road or vehicle traffic. This would leave too much potential unused, as pollutant emissions are often only redistributed in time or space. Optimisation of the intermodal composition of individual mobility must be the goal. This means that traffic management includes all mobility options – from personal cars to eBikes or pedestrian routes.

Frameworks or incentives are often to be created through regulatory measures (e.g. costs for parking, city tolls, discounted public transport tickets).

What is needed to implement eco-sensitive traffic management successfully?


From a purely technical point of view, measuring devices/sensors and control instruments/actuators are required. The sensor system triggers measures stored in the actuator system with near-real-time data. Of course, this data must be reliable/correct and continuously available. In addition to pure traffic data, e.g. from measurement loops in the lanes or floating car data, environmental data and other influencing parameters (e.g. weather) are recorded by the sensors for eco-sensitive traffic management.

The actuator system then initiates the measures – often predefined in models. These include, among others, traffic light controls (gatekeeper controls, green wave, adaptive controls), dynamic speed controls, or even the change of routing (variable message signs).

All this is often embedded in regulatory measures. These are, for example, parking fees, city tolls or access restrictions.


Yes, the necessary accompanying measures in the introduction of eco-sensitive traffic management should by no means be underestimated: Political courage is required, as it is to be expected that unrestricted individual mobility will be interfered with. Citizen information and participation help to increase acceptance. Often, perseverance is also needed in fighting for the budget and convincing internal administrations. Instead of the 10th expert report on traffic, it would be better to implement traffic management and observe and analyse the development. The results can be used for ongoing optimisation. We sometimes plan ourselves to death and then forget to act.

What would be the biggest mistakes in introducing eco-sensitive traffic management?


One should not start too late and wait until overload: A system that is already at the limit – or has already exceeded the limit – hardly reacts to so-called «soft» measures anymore.


As with all projects, a clear definition of goals is necessary, and all stakeholders must be brought on board. Data plays a key role. Therefore, the quality of the data is indispensable. The more data available, the better the models can be trained, and the control optimised. The biggest mistake, however, would be not considering traffic management’s environmental aspects. One can also start here with small steps.

What are the benefits of eco-sensitive traffic management in the first place?


One can assume a demonstrable reduction in air pollution – up to 40% in the case of NO2. (see EU Science Hub). In addition, and no less valuable, a wealth of data is collected through environmentally sensitive traffic management, which is available for cross-sectoral use at any time, e.g. for planning construction sites. Thus, better and fact-based decisions are possible, not only in the area of transport.


Eco-sensitive traffic management gets us on the road: it’s not just about technology and algorithms but requires acceptance and the will to change. A good starting point to put our responsibility toward the environment into action.

What approaches should there be more of in the future?


We should focus more on best practices and not reinvent the wheel for every traffic management project. Then we can also focus on continuous improvement.

The best results can be achieved by going beyond the management of individual traffic and rethinking mobility. This includes classic public transport and innovative concepts such as vehicle sharing and shared taxis.


Shared mobility in particular, has great potential. Studies show that the entire individual traffic of a city could be covered with less than 30% of the current vehicles if they were to be shared and thus increase the occupancy rate.

People don’t usually think of fun and the «joy of driving» when it comes to public transport. But it does not have to stay that way. We need to think about what would be necessary from a marketing point of view to make public transport interesting not only from a cost point of view but to establish it as an attractive and cool alternative!