This project is part of TEN-T Priority Project 18 and concerns the elimination of the main bottleneck in the entire Rhine-Main-Danube waterway. The main objective of this study (2007-DE-18050-S) is to make a concrete and independent assessment on the influence of different measures on navigation, as well as on the environment.This project, part of Priority Project 18 (Waterway axis Rhine/Meuse-Main-Danube), concerns the main bottleneck in the entire Rhine-Main-Danube waterway, which is from Straubing to Vilshofen. While the rest of the waterway has been adapted to 2.5 m water depth in recent years, the Straubing-Vilshofen section's water depth only reaches 1.6 m at low water levels. A water depth of 2.50 m can be reached only 165 days a year on average.After many years of interdisciplinary studies on the possibilities for improving shipping conditions, including flood control and implementation of a regional planning procedure, there is no agreement about the variant to be used. Thus, the main objective of this study is to make a concrete and independent assessment on the influence of different measures on navigation, as well as on the environment. Regional environmental impacts and the benefits of an effective inland waterway network (the potential of shifting goods from road to waterways, pollution reduction) will also be taken into account. In addition, the Federal Ministry of Transport, Building and Urban Affairs (BMVBS) has set up a monitoring group consisting of transport, economic and environmental experts in connection with the execution of the study.