| Popis: |
Planning urban snow removal, which is a complex optimization problem, is an important task in some countries like Sweden. A number of streets in a city must be cleared of snow by a limited number of vehicles and the tours for the vehicles must be planned in order to minimize the time and/or cost. Since modern real life city networks often contain parts that are trees, one can take advantage of the tree structure, in order to improve the computational eÿciency. In this paper, we study tree parts and develop a tree elimination procedure for the snow removal problem, to be used before searching for optimal tours. We have implemented the procedure and applied it to real life city networks. The numerical results compare obtaining feasible tours for real life city networks with and without tree elimination. It shows that the total solution time is signifcantly decreased with tree elimination, and larger areas can be handled. |
