After establishing the EIA(Environmental Impact Assessment) act in the Federal Republic of Germany there still remain methodical and substantial deficits. So nearly every environmental impact study went to be a matter of experiments. The requirement for standardization of data sampling and evaluation has permanently been increasing. This is meant to ensure quality standards for the assessment of environmental impacts as well as to maintain reliability required by the projecting company. Such a harmonization is of special importance because of the strongly accelerated expansion of traffic infrastructure caused by the reunification of Germany. That is why the guideline "EIA carried out" for the German Railways company is in process of development This guideline, focussing on practical demands, comprises impacts of railways, adequate sets of indicators, feasible tools for the prognosis and evaluation of environmental reactions. "EIA carried out" will be introduced not only as a manual but also through workshops and pilot studies.