Routing and driver break scheduling with working and driving regulations: A flexible approach for various general pickup and delivery problem variants

Abstract

This paper provides a solution to the driver break scheduling problem that can be integrated into current solvers for the generalised pick-up and delivery problem (GPDP) with a negligible increase in development costs. The driver break scheduling problem affects truck drivers who are required to adhere to working time and/or driving time regulations that oblige them to take mandatory breaks. These regulations are in force in many countries across the European Union, Great Britain, Australia, New Zealand, and the United States. We propose a flexible solution strategy that combines routing with driver break scheduling, taking into account both Regulations (EC)561/2006 and 2002/15/EC within a single day of operation. We deliberately incorporate driver breaks into the routes generated, with the aim of minimising route duration. The method proposed in this paper is particularly beneficial for the solvers that have not initially implemented driver break rules but need to introduce this functionality to accommodate customers, given the critical nature of driver break rules for effective scheduling. This is a flexible approach because the method proposed here can be applied directly to any individual route and at any stage of the scheduling process. For instance, it can be used during the constructive heuristic or the improvement heuristic phases. It is also applicable at the column generation stage of an exact method after a route has been constructed. This method is particularly beneficial when a human scheduler wishes to make manual adjustments along a single route, such as adding or removing an order from the route. Experimental analyses, grounded in two benchmark instances, affirm the efficacy of the proposed method. Results indicate that the method yields a 6.1% decrease in distance, a 1.7% reduction in duty time, and a 1.1% decrease in the number of unassigned tasks when contrasted with the standard compliant approach. We also offer guidance on how to tailor this method for driver break scheduling in accordance with the regulatory standards of Australia and New Zealand.