Traffic-related Emissions and Immissions 2002


Model Input

The results of street measurements show that the concentration levels set forth in Guideline 99/33/EG and the 22nd BImSchV are exceeded at a large number of main traffic streets, especially soot levels. As technical measurements on all streets in the city are not possible for cost reasons alone, the pollution emissions from all of the main street networks in Berlin were established using emission and extension calculations. Thereby the streets where, most likely, legal limits are exceeded, and those where limits are met, are determined.

To achieve this, the said measurements are supplemented with model calculations in all traffic filled streets in which limits are potentially exceeded. However, even in a traffic filled street ravine, the background pollution produced by other sources in the city and by the long distance transport of pollution plays an important role. Therefore, to plan the improvement of air quality in Berlin, a system of models was developed that can calculate both the large scale influence of distant sources as well as the contribution of all emitters in the city, even in traffic filled street ravines. For such an estimation of all main streets (Screening), the aptly designed modular program system IMMIS▪▪▪ is suitable.

IMMIS▪▪▪ is a Screening program system for the evaluation of pollution caused by street traffic. It was developed specifically for applications of traffic related evaluations. With the help of this program – provided the necessary input data is known – a rapid computation of the emission load is possible for both individual streets and comprehensive street systems.

Herewith pollution on both sides of the street is calculated for each point at an elevation of 1.5 m and a distance of 1.5 m from the edge of the building (see figure 6). The average of the calculated emissions at these two points is regarded as a characteristic estimation of the emission pollutants in this section.

Pollution from traffic in street ravines was modelled with the IMMIScpb program. It facilitates the calculation of hourly levels of pollutants produced by local traffic, as arbitrary points (receptors) are located in street ravines with differing building heights and differing spaces between buildings which allow the passage of wind on the basis of easily accessible meteorological data. The emission levels for each section of street are additional and necessary input data. The emissions were calculated with the IMMISem program from actual data. The pre existing pollution from the city is made up of: the additional pollution measured by the street ravine model; pollution caused by local street traffic; and the urban background calculated with the IMMISnet program.

Evaluation Based on an Index

The map derived from these works shows the spatial distribution of traffic caused pollution for NO2 and PM10. For both substances a collective evaluation was conducted. The resulting index weighs the calculated concentrations of both pollutants according to their readings from about 7000 street sections of the main traffic network for 2002 and it adds the quotients. An index of 1.00 results when both components reach 50% of the limit. All sections that show a reading exceeding 2.00 require special attention in the future (compare effects on human health).

Data Display

The results capture detailed information regarding selected sections. (With the appropriate button, mark one or more of the colored count sections with the right mouse button and confirm with the left. If you press the “actual data display” button the selected data will appear on the right side.) Beside the key number of the section, the following parameters are represented:

  • name of the municipality where the section lays;
  • street name;
  • average daily traffic volume (DTV) for automobiles, trucks and two-wheeled vehicles;
  • number of BVG busses per day;
  • emission data for 2002 related to the following substances:
    • benzene;
    • soot;
    • carbon Monoxide;
    • carbon Dioxide;
    • nitrogen Oxide;
    • particles (total); and
    • particles (exhaust);
  • the calculated e for 2002 related to the following substances:
    • the annual average amount of NO2;
    • the 24 hour amount of PM10; and
    • the annual average amount of PM10;
  • the trend calculations of emissions for 2005 and 2010, in each case related to the following substances:
    • the annual average amount of NO2;
    • the 24 hour amount of PM10; and
    • the annual average amount of PM10.