External effects in transportation are effects from activities which are not bared by the traveller himself, but which are instead shifted to other people, other times or other regions. Examples are accidents, damages by space separation or air and noise emissions. The current research is already well developed in the field of external effects in transportation. Areas which are barely covered by the research so far are the following questions: Which socio-economic groups cause more effects than average? Which socio-demographic groups have to bear more effects than others? Systems in a free market economy are based on decentralized decisions of independent stakeholder concerning the use of scarce goods and resources. The individual costbenefit consideration of the market participant concerning the decision determines the behaviour. The price paid for an output represents the expenditure. The price does not represent the complete expenditure in case of external costs and a non-optimal level of transportation is consumed. Aditionally, external costs impose a second important problem on society: the environmental burden caused by transport activities is not distributed evenly neither between different socio-economic groups in society nor between regions. The goal of the PhD work is to represent the distributional effects external transport costs cause in society. The impact course starts with the generation traffic and its environmental effects by certain socio-economic groups and geographic regions, continues with the route choice and ends on the side of the affected individuals which can be categorized by socio-economic groups and regions again. The result will show which groups cause economic losses of certain magnitudes among each other. The analysis is currently done for a large German city. This scope is expedient because the serious environmental effects like noise or air emissions have a direct impact on the liveability in the city. Many approaches to improve the situation were tested during the last few decades. They were only partly successful and road pricing is seen as a more promising tool today. However, concerns about social equity of a road tolls are often raised in science and local politics. More knowledge about today’s distributional effects is needed because it plays an elementary role for the design of a charging model and the distribution of the revenues. The research design has three levels. Level 1: The city council has a transportation model which can be used to derive traffic flows between all zones and on all links. A system is developed to combine traffic flow with the socio-economic background of the travellers like gender, age groups, nationalities, income and level of education. By complementing the data with information about the registered vehicles, the traffic on a certain link can be allocated to the generating socio-economic group. Level 2: Maps showing the different effects of traffic already exist and each one of them is compiled and joined with Level 1 by using GIS (e.g. noise maps for EU- environmental noise directive). Level 3: An appropriate zoning design has to be developed for each type of effect in order to determine the socio-demographic groups which are affected. The residents next to the road in case of noise are one example. At this point, level three has to be joined with the other levels and it is possible to follow the whole course of effects from the generator all the way to the affected individuals. The PhD project is still in progress. An extensive literature study will be completed soon and first calculations for level 2 and 3 are currently done. A few results from the analysis are already available. The paper will focus on the planned research design and the methodology to measure distributional effects of external costs. Results from the literature review will be presented and some preliminary findings from the data analysis will be shown.