Monitoring system could help cities manage emissions without banning older vehicles

How can vehicle emissions be reduced without necessarily having to change cars? A new monitoring system, developed by Politecnico di Milano and described in a study published in the journal Scientific Reports, offers a concrete answer that makes sustainable mobility accessible to all.

The proposed methodology uses a virtual sensing system to accurately estimate emissions of carbon dioxide (CO₂) and nitrogen oxides (NO_x), using very simple instruments, exceeding the limits of the Euro classification alone.

Thanks to the use of small telematic devices equipped with GPS for positioning and an inertial unit for measuring acceleration, the system measures emissions based on actual driving behavior.

Using a large database of data collected from over 8,000 private vehicles equipped with black boxes in Italy and analyzed for over 11 million journeys, the algorithms calculate the real environmental impact of each vehicle. UnipolTech, the telematics division of the Unipol Group, provided a unique data set in terms of accuracy and amplitude, with information on speed, distance traveled and driving style, which allowed the proposed algorithms to be validated.

“The methodology provides a concrete answer for those who want to do their bit for sustainability without having to change their vehicle immediately. This means sustainable mobility for all,” explains Professor Silvia Strada, lead author of the study. “Empowering drivers to manage, understand and improve their environmental impact opens up an inclusive transition to sustainability.”

The system uses three key performance indicators (KPIs): fuel consumption, CO₂ emissions and NO_x emissions. These KPIs show that emissions and fuel consumption depend not only on vehicle technology but also on driving behavior, providing a personalized assessment of environmental impact. For example, there is a “green speed,” i.e. an optimal speed range between 50–75 km/h, which is more efficient in terms of both consumption and emissions.

This monitoring system has many potential applications for cities: councils can use it to manage emissions in restricted traffic areas and adjust access and parking fees based on the actual environmental impact of vehicles, without banning anyone from driving altogether. In addition, the indicators could support incentives for virtuous driving, while respecting the technological neutrality of the car.

As part of a sustainable transition, the European Union has set ambitious targets: a 90% reduction in transport emissions by 2050, as required by the Green Deal. This system is a direct response to this need, making monitoring accessible and fair to those who are currently unable to invest in zero-emission vehicles.

The new approach shows that an older vehicle can still be sustainable if driven carefully and for limited distances, challenging the current paradigm based solely on Euro classes.

This system is now a concrete tool for those who want to drive more responsibly and for cities that want to reduce emissions. The proposed emission estimation algorithms can form an essential basis for sustainable mobility, contributing to a more inclusive and less impactful management of urban mobility and beyond.