Road dust load dynamics and influencing factors for six winter seasons in Stockholm, Sweden

Sara Janhäll
Max Elmgren
Christer Johansson
Michael Norman
Sanna Silvergren

Traffic related non-exhaust particulate sources and road dust are an increasingly important source for PM10 air pollution as exhaust sources are decreasing due to regulations. In the Nordic countries, the road dust problem is enhanced by use of studded tyres, causing increased road wear and winter road maintenance including gritting. Efforts to reduce road dust emissions requires knowledge on temporal and spatial road dust load dynamics. The city of Stockholm, Sweden, has therefore financed seasonal (October to May) road dust sampling to be able to optimize their winter and spring time street operation measures for reduced road dust emissions. This work describes the outcome of six seasons (2011/2012–2016/2017) of road dust sampling in five central streets using the VTI wet dust sampler (WDS).The results show that road dust load, expressed as DL180 (dust load smaller than 180 μm) has a seasonal variation with the highest loads (up to 200 g/m2) in late winter and early spring and a minimum (down to about 15 g/m2) in early autumn and late spring. The dust load varies between streets and is depending on pavement surface properties. On a smaller scale the dust load has a high variability across streets due to differences in rates of suspension from different parts of the road surface, with low amounts in wheel tracks and higher in-between and outside the tracks. Between 2 and 30% of the DL180 is smaller than 10 μm and could directly contribute to PM10 emissions. In general, higher road surface texture leads to higher dust loads, but the condition of the pavement (e.g. cracks, aggregate loss) might also have an effect. A new, wear resistant pavement accumulated markedly higher road dust amounts than a several years old pavement. This paper closes with a discussion on the complex relation between road dust load and PM10 concentrations and a discussion on the challenges and comparability of road dust sampling techniques and measures.



Social sustainability and just mobility

Welcome to a research workshop on Social sustainability and just mobility, 8–9 October 2019 in Linköping, Sweden

European Road Profile User's Group, ERPUG

Welcome to the sixth ERPUG meeting in Vilnius, Lithuania. 

Vision Zero for Sustainable Road Safety in the Baltic Sea Region

The second Vision Zero for Sustainable Road Safety in the Baltic Sea Region conference will be held in Tallinn, Estonia. VTI is part of the programme committee. 



Knowledge in the fight against microplastics from road traffic

The Government has commissioned VTI to develop and disseminate knowledge regarding the emission of microplastics from road traffic.


How to make autonomous vehicles coexist with other traffic

The road infrastructure must be prepared for self-driving vehicles – especially in the beginning when the concepts are still new. Researchers are contributing to this through CoEXist, an EU-funded research project in which VTI participates as the largest...


Electric roads: ‘Standardisation is an important factor for a future European transport system’

VTI employees recently arranged a workshop in Brussels on the standardisation of Electric Road Systems (ERS). ERS has become increasingly relevant as a possible method for reducing the transport sector's environmental impacts, especially in terms of climate...


Research on passenger and freight transport research

Shift2Rail is a European railway project that works actively to create innovations within the railway sector. IMPACT-2 is a project within Shift2Rail that follows and evaluates the innovation projects. How are the innovations coming along? Are they beneficial...


How vehicles can avoid accidents on newly paved roads

Friction is an important property for road safety. VTI has investigated how roads change in the first few weeks after surfacing work has been completed. Researchers recommend posting warning signs when the road is opened and waiting at least three weeks to...


VTI contributes to study on older drivers and accidents

On behalf of and in collaboration with the Swedish Transport Agency, VTI has carried out a study of older drivers and the link between illness and traffic accidents. The Transport Agency has now published the results.