Mann+Hummel has developed roadside filters which can reduce traffic emissions by up to 40% and – it says - could make vehicle bans from inner cities unnecessary.

The company has installed Filter Cubes at a busy road junction in Stuttgart to reduce the level of fine dust pollution.

The filter specialists have now further developed the technology and integrated a newly-developed combifilter medium which retains fine dust and also filters NO2 out of the air.

This will be incorporated in the Stuttgart Filter Cubes by the summer, and before the end of the year will also be used in a pilot project in Ludwigsburg.

Werner Lieberherr, CEO of Mann+Hummel, said: “At Mann+Hummel, as a filtration expert with almost 80 years of experience, we are transferring our expertise to new areas.

“With our technology for reducing NO2 and fine dust pollution, we can offset 40% of traffic-related emissions.

“In this way, we contribute to the protection of local residents and also present a real alternative to driving bans in city centres.”

In a pilot project, 17 filter columns were installed at the Neckartor road junction in Stuttgart at the end of 2018.

Since 2017, the measuring station at the location had repeatedly exceeded one of the three limit values for fine dust (number of exceedances of the PM10 daily mean value).

The pilot project is designed to investigate whether the technology can be used to reduce the local fine dust pollution.

The first assessments of the project indicate that the filter cubes reduce the local particle concentration by 10% to 30%, which corresponds to 40% of all fine dust particles caused by heavy traffic at the road junction.

The majority of these particles are due to braking or road abrasion and, to a lesser degree, exhaust emissions.