Traffic-related Emissions and Immissions 2005


Use of the Model

The results of street measurements show that the concentration levels set forth in Directive 99/30/EG and the 22nd BImSchV, especially soot levels, are exceeded at a large number of primary roads. Since measurement-based investigations are, for cost reasons, not possible on all streets in the city, the pollution immission from all the primary roads networks in Berlin were ascertained using emission and dispersion calculations. Under this process, those streets are ascertained where the legal limit values are almost certain to be exceeded, or where they will be met.

To achieve this, these measurements are supplemented with model calculations in all traffic filled streets in which limits are potentially exceeded. However, even in a traffic filled canyon street, the background pollution produced by other sources in the city, and introduced by the long distance transportation of pollution, is an important factor. 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 and the contribution of all emitters in the city, even in traffic filled canyon streets. For such an estimation of all primary roads (“screening”), the aptly designed modular programme system IMMIS▪▪▪ is suitable.

IMMIS-Luft▪▪▪ (air) is a screening programme system for the evaluation of pollution caused by road traffic. It was developed specifically for application in the context of traffic related assessments. With the aid of this programme – provided the necessary input data is known – a rapid calculation of the pollution immission is possible for both particular streets and for comprehensive street systems.

In this process, the pollution immission is calculated on both sides of the street for one point on each side, at an elevation of 1.5 m, and at a distance of 1.5 m from the edge of the building (cf. Figure 6). The mean of the calculated immission at these two points is considered the characteristic estimate of the immission pollution in this section.

Traffic-caused air pollution immission in canyon streets was modelled with the programme segment IMMIScpb. It enables the calculation of hourly values of pollutant immission produced by local traffic at any receptor in a canyon street with varying building heights and with spaces between buildings which allow the passage of wind, on the basis of easily accessible meteorological quanta. An additional required input quantum is the emission level for each section of the street. The emissions were calculated from the current traffic data using the programme segment IMMISem. The pollution produced by the city is derived from the sum of the additional pollution measured using the canyon street model, the local street traffic, and the urban background pollution calculated using the IMMISnet programme.

Evaluation Based on an Index

The map drafted using this process shows the spatial distribution of traffic caused air pollution for NO2 and PM10. A comprehensive assessment was conducted for both substances. The index developed weighs the calculated concentrations of both pollutants according to their readings from about 7,000 street sections of the primary roads network for 2005, and adds the quotients. For example, if the two components both reach 50 % of the limit, an index of 1.00 will result. All sections that show a reading in excess of 2.00 will require special attention in the future (cf. Effects on Human Health).

Data Display

The data display includes detailed information on selected street sections. (Click on the appropriate button/s with the right mouse key to mark one or more of the coloured count sections, and then confirm with the left mouse key. If you press the “Factual data display” button, the selected data will appear on the right side.) The following parameters are provided next to the key number of each section:

  • name of the borough where the section is located;
  • street name;
  • average daily traffic volume (DTV) for automobiles, lorries and two-wheeled vehicles;
  • number of BVG busses per day;
  • emission data for 2005, in reference to the following substances:
    • benzene;
    • soot;
    • carbon dioxide
    • nitrogen oxides;
    • particles (total); and
    • particles (exhaust);
  • the calculated immission for 2005 in reference to the following substances:
    • the annual mean for NO2;
    • the 24 hour value of PM10; and
    • the annual mean for PM10;
  • the trend calculations of immission for 2015, each in reference to the following substances:
    • the annual mean for NO2;
    • the 24 hour value of PM10; and
    • the annual mean for PM10.