Motor Vehicle Traffic Emissions Registry
The current Motor Vehicle Traffic Emissions Registry was compiled anew on the basis of traffic counts for 2009, because according to experience to date, this category of polluters contributes significantly to particulate and nitrogen oxide pollution. Traffic counters have been installed at many locations on the primary roads of Berlin since 2001. These data serve to make the current traffic patterns in Berlin accessible, and to incorporate them into traffic management. This information is evaluated in the Office of Traffic Management (VKRZ), and is used to inform the populace (especially drivers) of traffic conditions and provide routing recommendations to avoid traffic jams via radio broadcasts, the internet, and centrally located sign boards. The enhancement of the VKRZ serves the goal of dynamically controlling traffic according to the current traffic situation and volume.
Ascertainment of traffic volume
Since 2002, the data from approx. 400 detectors at about 300 locations within the Berlin primary road network have been available at the Traffic Control Office. Many of these detectors distinguish between cars and lorries, and can be used for approximate annual traffic counts.
In addition for 2009, traffic count figures for car, lorries, buses and motorcycles from an official count by trained persons at many intersections ordered approximately every 5 years by the Senate Department for Urban Development and the Environment were available. Compared with counts by detectors, this official traffic count has the advantage of being better able to distinguish between lorries of more or less than 3.5 t, respectively, and other motor vehicles. For 2009 therefore, this traffic count was selected as the basis for an “Emissions Survey for Motor Vehicle Traffic 2009 in the framework of the Air Quality Plan 2011-2017”, as had been the case for the previous Emissions Registers for Motor Vehicle Traffic in 1994, 1999 and 2005. The exhaust emissions were then ascertained as follows:
- The extrapolation of the point-related intersection counts to the entire Berlin primary road network with a traffic-flow computational model (VISA) by the Senate Department for Urban Development provided the results showing the mean daily traffic figures (DTV) and the proportions of lorries for all major streets.
- The ascertainment of the segment-related pollution of the primary road network with regular bus traffic of the Berlin Transit Company (BVG) was calculated on the basis of the bus schedule data for 2009.
- The calculation of the emissions with the emission factors from the UBA manual for emissions factors with consideration for the type of road and its function, was ascertained with the aid of the program IMMISem/luft.
Detailed information on the ascertainment of motor vehicle emissions, the emission models for the primary and secondary road networks as well as the ascertainment of exhaust, abrasion and resuspension emissions has already been provided in the 2011 Edition (SenStadtUm 2011).
The new method of calculating emissions developed for this registry is also a suitable basis for dispersion calculations to determine the extent of pollution along streets and was also used for the illustrations in the map “03.11.2 Traffic related Air Pollution – Index of air pollution for PM10 and NO2” (Edition 2011) (SenStadtUm 2011). The extensive reorganisation of the calculation methods used for this purpose permits only very limited comparisons with previous emissions surveys, because these were based on a much simpler method of calculation.
In the meantime, it has turned out that particularly in actual urban traffic situations newer diesel vehicles exhibit far higher specific NOx emissions than predicted in 2009. This led to a significant overestimation of the NO2 reduction along primary roads, but as a consequence also in residential areas.
In the meantime, the NOx emission factors for Euro 5 vehicles and also for the Euro 6 vehicles mandated beginning on September 1, 2015 have been corrected upwards, in particular for diesel cars and light commercial vehicles. These emission factors were first published in the summer of 2014 in the UBA manual Emission Factors of Road Traffic (Version 3.2) (INFRAS 2014).
Moreover, new counts of the Berlin fleet composition were available for 2012, which allowed the NO2 pollution in Berlin to be recalculated for 2015 and for the prognosis year 2020.
The aim of the calculation was to allow a more reliable statement about the number of residents affected by excessive NO2 values to be made. A further aim was to check the hypothesis, based on the old calculations, that in 2020 no-one will be exposed to NO2 concentrations above 40 µg/m3 in Berlin anymore.