CAR Model

Calculation of air pollution from road traffic

CAR (Calculation of Air pollution from Road traffic) is a screening model for the air pollution from road traffic in cities and communities in Flanders. It was developed in 2006 together with TNO for the Flemish government on the basis of the Dutch CAR II model. In 2009-2010 the model was updated, resulting in CAR Flanders version 2.0.

Its aim is to be easy to use and to quickly gain insights in the air pollution along traffic corridors. Air pollution is calculated for one or more road sections on the basis of traffic characteristics (intensities, traffic composition and level of service) and road section characteristics (location, street name, road configuration). For PM10, PM2,5  as well as NOx, the yearly averaged concentrations, the number of times the limit is exceeded and the margins of excess are calculated. The effects of traffic measures on air quality can be estimated by changing the traffic characteristics in the input. The calculation can be done for 2007, 2010, 2015 and 2020.

In version 2.0 of the model all input data was updated (vehicle stock, emission factors, background concentrations, meteorological data). The calculation of PM2,5 concentrations was added and the calculation years were updated (2007 instead of 2005 and 2020 was added). Furthermore, v2.0 allows better assessment of the effect of congested traffic. Finally, a scenario module was added in version 2.0 of the software to calculate the effect of measures that have an impact on the composition of the vehicle stock in a certain street. The module is primarily aimed at scenario calculations, but can also be used for better fitting of the input data to the local situation.


A new version (version 3.0) of the model is available on the LNE website:



2006; update in 2009-2010

funded by

Flemish Government, Environment, Nature and Energy Department




Filip Vanhove

+32 16 31.77.35
reference: 05.11-08.55