This text develops the mathematical implications of barriers to the geometrical and analytical characteristics of continuous location problems. Theoretic as well as algorithmic approaches are utilized to overcome the described difficulties for the solution of location problems with barriers.

Inhalt
and General Results.- Measuring Distances.- Shortest Paths in the Presence of Barriers.- Location Problems with Barriers: Basic Concepts and Literature Review.- Bounds for Location Problems with Barriers.- Solution Methods for Specially Shaped Barriers.- Planar Location Problems with Polyhedral Barriers.- Location Problems with a Circular Barrier.- Weber Problems with a Line Barrier.- Solution Methods for Special Distance and Objective Functions.- Weber Problems with Block Norms.- Center Problems with the Manhattan Metric.- Multicriteria Location Problems with Polyhedral Barriers.- Application.- Location with Barriers Put to Work in Practice.