... calculation of traffic induced air pollution
© Lohmeyer GmbH


  • PRKAS is available as an extension in SELMAGIS
  • PROKAS consists of the modules PROKAS_V, PROKAS_B and PROKAS_E.
  • PROKAS_V is used for the calculation of the traffic induced background concentration by road nets and the calculation of the additional street concentration in terrain without major buildings.
  • PROKAS can handle an arbitrary number of road segments.
  • PROKAS uses a Gaussian dispersion model according to the VDI guideline 3783/1 "Dispersion modelling for air quality management" with special modifications to account for vehicle traffic.
  • For the determination of the additional street concentration in densely built up terrain (partly or completely closed front of buildings, street canyons) the supplementary modulel PROKAS_B is available. PROKAS_B bases on the result of dispersion calculations with the microscale flow - and dispersion model MISKAM for typified building structures.
  • On the basis of a local dispersion statistics PROKAS_V and PROKAS_B calculate the statistical parameters of the air pollutant time series (annual mean and 98%) in a way, suitable for comparison with the limit values of the EU Air Quality Directives.
  • Import interface is available for MOBILEV, for ARCINFO, IMMI and VISUM under preparation.
  • PROKAS_V and PROKAS_B are capable to run on a PC with WINDOWS 2000, XP and 7.
  • Detailed description


  • In case of a partially or totally closed (street canyon) front of buidlings adjacent to the road the background concentration is calculated by PROKAS_V. For the calculation of the additional street concentration the supplementary module PROKAS_B is available. PROKAS_B bases on the result of dispersion calculations with the microscale flow - and dispersion model MISKAM for typified building structures. It calculates for example the annual mean and the 98-percentile of the traffic induced air pollutant concentrations in a height of 1.5 m and in 1 m distance to the nearest building. The superposition of the background concentration by the surrounding net of roads and the additional street concentration is done time correlated, it is not done via a parametrization.
  • The typified building scheme differenciates between street canyon as adjacent buildings on one or both sides of the road with different ratios of (height of the buildings)/(width of the canyon) and different ratios of (gaps between the buildings)/(length of the road section).
  • The dimensionsless concentrations c* were taken from wind tunnel measurements with idealized building structures and calculations with the numerical model MISKAM. Validations were executed using the results of field measurements in Hannover, Karlsruhe and Dresden. The correlation between the calculated and the monitored concentrations is satisfying.


  • PROKAS_E calculates traffic induced emissions of relevant pollutant substances for complext road networks considering emission factor tables.
  • The emission factor tables ar defined an the basis of  the "Handbuch für Emissionsfaktoren des Straßenverkehrs" (HBEFA, INFRAS).
  • For particulate emissions (PM10 and PM2.5), non-engine-related emissions (abrasion, swirling up of road dust) are also relevant. These are calculated according to the state of the art.
  • Irrespective of the temporal influence, the differences between region-specific fleet compositions and the national average are relevant. Accordingly, the proportion of diesel cars in Saxony, for example, is the lowest in Germany at 19% in 2010. The German average for that year was 27%. In low emission zones (LEZ) , the distribution of vehicles according to EURO emission standards also deviates considerably from average values. We therefore offer you the calculation of emission factors on the basis of a region-specific fleet composition. The following options are available:
  1. To take into account the large region-specific differences in the proportion of diesel cars and the vehicle composition according to EURO emission standards, state-specific fleet compositions are calculated on the basis of the Motor Transport Authority's and the HBEFA urban mileage factors. Based on this, the forecast years can be extrapolated using the predicted fleet development of the HBEFA.
  2. The aim of low emission zones is to change air pollutant emissions through a targeted change in fleet composition. For this reason, the vehicle fleet in low emission zones differs significantly from the average fleet composition in Germany and the individual federal states. Based on the average fleet compositions calculated in 1., an emission factor data set can be calculated for each commissioned reference year on the basis of the environmental zone fleet composition.
  3. Fleet compositions for other specific aspects such as truck transit bans for certain size classes or the consideration of the municipal bus fleet can be taken into account individually according to the respective issue.

see detailed decription

Downloads (Manual, Trial full version)

  • Karlsruhe

    An der Rossweid 15
    76229 Karlsruhe

  • Dresden

    Friedrichstraße 24
    01067 Dresden

  • Bochum

    Wasserstr. 223
    44799 Bochum

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