AbstractA capacitated node routing problem, known as the vehicle routing or dispatch problem, has been the focus of much research attention. On the other hand, capacitated arc routing problems have been comparatively neglected. Both classes of problems are extremely rich in theory and applications. Our intent in this paper is to define a capacitated arc routing problem, to provide mathematical programming formulations, to perform a computational complexity analysis, and to present an approximate solution strategy for this class of problems. In addition, we identify several related routing problems and develop tight lower bounds on the optimal solution.