Finding and Assessing Route Alternatives

The main goal of this project was to carry out a study of the environmental impacts of the new by-pass road L4 in Goetterswickerhamm, North Rhine Westfalia, in the Federal Republic of Germany, using two methods of environmental impact assessment. These methods are "analysis of ecological risks" and "analysis of utility values (2nd generation)". Another goal was to find and assess alternative routes to this road with the objective of taking a decision on which of the routes demonstrates the most environmental compatibility. The use of the two methods and the investigation of their realization was carried out with the use of the geographical information system ARC/INFO. It was not an objective of the project to achieve a model of assessment in which individual factors are produced and evaluated. The two methods were applied separately and this led to the production of two different space resistance maps. These maps make it possible to deduce variants of routes that demonstrate minimum conflicts. Different route alternatives were arrived at, but what is noteworthy is that a decision about which route alternative demonstrates that the most environmental compatibility alternative could only be taken, not without argument, through the analysis of ecological risks method. The difficulty in taking a concrete decision through the analysis of utility values method arose from a 0·3 difference in the total utility values of three route alternatives. The project orientated itself by a study that was carried out by the planning office of Froelich and Sporbeck.