Road cleaning and dust-binding measures in Trondheim, Norway

Air quality issue

The city of Trondheim measured high particulate matter values from the early 1990s, when air quality measurements began. Through targeted measures, the city managed to reduce these values sharply.

Example of measures taken

In 2013, Trondheim implemented road cleaning and dust-binding measures to improve local air quality and reduce the levels of particulate matter. These measures consist of sweeping and suction, both with and without the use of water to rinse road surfaces. Dust suppression chemicals are deposited on the road surface to keep the surface moist and to bind dust. To be the most effective, measures also include requirements to remove snow and sand deposits from the roads. 

Costs and trade-offs

In 2017, the cost of road cleaning for 22.6km of roadway was €330,000, more expensive per km than typical winter road cleaning measures. It is difficult to predict the need for road cleaning over the long term, as this is dependent on meteorology and air quality forecast accuracy at a shorter time scale. A consequence of these measures is the run-off of magnesium chloride solution, which may have an impact on local aquatic ecosystems only at higher concentrations than those applied for the measures.

Who was involved?

The maintenance department of Trondheim municipality was responsible for implementing the measures, while the Norwegian Public Roads Administration followed up with an impact assessment. Trondheim municipality is the authority responsible for ensuring compliance with air quality limit values, while the road authorities are responsible for reducing and monitoring emissions from roadways.

Lessons learnt

• Trondheim city maintenance department successfully adapted road cleaning machinery to clean multiple surfaces, not just roads.
• This mitigation measure can be applied to all areas with road dust problems, in response to address poor air quality.
• It is difficult to assess the impacts of the measures implemented, as various other measures to address air quality were being implemented at the same time.