NORTRIP - Non-exhaust road traffic induced particle emissions: development of a model for assessing the effect on air quality and exposure

Christer Johansson
Cecilia Bennet

The PM10 concentrations exceed the EU limit values in almost all countries in Europe. Especially, in many Nordic cities, non-exhaust particle emissions are the main reason for high PM10 levels along densely trafficked roads. This is connected to the use of studded tyres and winter time road traction maintenance, e.g. salting and sanding. The ultimate aim of the project has been to develop a process based emission model, that can be applied in any city without site specific empirical factors, for management and evaluation of abatement strategies and that is able to describe the (non-exhaust) emissions on an hourly or at least daily basis with satisfactory accuracy. The model is built upon existing road dust emission models, combined with field and laboratory measurements. The major features of the model are:

  • Road dust and salt loading is calculated based on a mass balance equation
  • Production of road dust, and subsequent emissions, are based on the total wear of road, brakes and tyres
  • Maintenance activities (e.g. salting, sanding, cleaning, ploughing) contribute to the mass balance as well as processes such as drainage and splash/spray
  • Retention of road surface dust is dependent on the surface moisture content
  • The road surface moisture is calculated based on a mass balance equation for surface water and ice
  • Evaporation is based on energy balance modelling of the road surface
  • Maintenance activities (e.g. cleaning, ploughing, salt solutions) and processes (e.g. drainage, splash/ spray) are included in the moisture mass balance
  • The impact of salting on both dust retention and melt temperature is considered



ERPUG 2017

The five year anniversary of  European Road Profile Users' Group (ERPUG) Forum will take place at Ramboll head quarter, Copenhagen, Denmark October 19-20, 2017. 



Vehicle Driver Monitoring: sleepiness and cognitive load

To prevent road crashes it is important to understand driver related contributing factors, which have been suggested to be the critical reason in 94 per cent of crashes. The overall aim of the project Vehicle Driver Monitoring has been to advance the...


Tomas Svensson new director-general

Tomas Svensson was today appointed Director-General of VTI. Tomas has been acting Director-General since January 2017. 


Crash testing bicycles at VTI

For the first time single bicycle crashes have been simulated at the VTI crash safety laboratory.


A case study exploring firefighters’ and municipal officials’ preparedness for electrical vehicles

A VTI-study presents a social perspective on new vehicle technology. It explores the self-reported preparedness of the fire departments (i.e., rescue services) in Sweden’s three largest cities regarding rescue operations involving electrical vehicles (EVs).


Pioneering research on and about bicycles at VTI

Under what circumstances might cyclists lose tyre grip? What actions could then be taken to prevent a crash? VTI is currently developing a theoretical model of the behaviour of bicycle tyres during braking and steering in different situations and on different...


Virtual pedestrians create efficient stations

If more people are to choose sustainable travel, then the public transport stations of the future must be designed so that pedestrians can get where they are going quickly, without congestion or queues. The Swedish Road and Transport Research Institute (VTI)...