Variable neighborhood search for the pickup and delivery traveling salesman problem with LIFO loading

This paper addresses a variation of the traveling salesman problem with pickup and delivery in which loading and unloading operations have to be executed in a last–in–first–out (LIFO) order. We introduce three new local search operators for this problem, which are then embedded within a variable neighborhood search heuristic. We evaluate the performance of the heuristic on data adapted from TSPLIB instances.