CAR Smog: system for on-line extrapolation from hourly measurements to concentrations along standard roads within cities

As an alternative to extensive monitoring a calculating system called CAR Smog was developed. This system extrapolates the results of hourly measurements of CO, NOx and NO2 from 13 street stations of the Dutch National Air Quality Monitoring Network to air pollution levels in busy (standard) streets in all large Dutch cities. Basic assumptions are that hourly fluctuations in emissions, dispersion characteristics and the atmospheric NO2 formation rate in all streets will approximately be the same. Measured and modelled concentrations agree well with each other, even during smog episodes. Since 1993 the system has been in use in The Netherlands and the results are available through viditel within a timespan of one hour.