A NO2 source apportionment tool for road transport emissions

CONCAWE approached VITO in 2017 to develop an EU-wide interactive source apportionment tool that would allow to assess the contribution of the NOx emissions from various vehicle categories, fuel types, and Euro standards, on the NO2 levels everywhere in Europe. 

VITO was in a unique position to offer this service as the atmospheric modelling team had just developed QUARK (Quick Urban AiR quality using Kernels) which allows fast modelling of NO2 levels across all of Europe down to street level. The resulting web application contains baseline data for 2015 and future years 2020, 2025 and 2030.

Extensive update

In 2021, CONCAWE requested an extensive update to provide further insights for their members. The application was extended with local and EU-wide scenario functionalities to assess the impact of traffic measures to 900+ ‘cities’ in Europe, such as:

  • Urban Access regulation – e.g., “LEZ-like” scenarios
  • Activity changes – e.g., modal shift, road pricing
  • Impact of the extreme COVID-19 lockdown measures on the NO2 levels at the start of the pandemic due to the dramatic decrease of traffic.
  • Introduction of a more stringent “new Euro standard”


Client: Concawe

Year: 2017 - 2022