Our paper (joint work with Nico Dellaert, Fardin Dashty Saridarq and Theo Crainic):

Branch & Price based algorithms for the Two-Echelon Vehicle Routing Problem with Time Windows

just got accepted for publication in Transportation Science!

Consider a multi-echelon distribution system in which the transportation chain is split into multiple echelons. In each echelon, goods are consolidated at facilities and transferred to customers or another set of facilities. Vehicles with different characteristics (e.g., capacity) are used in each echelon to transfer goods. Such systems bring signicant economic advantage due to the efficient use of vehicle capacities at each echelon. An important problem is how to efficiently route vehicles in each echelon to distribute goods to their nal customers.

In this paper, we consider a two-echelon vehicle routing problem (2E-VRP) with time windows for customers. The first echelon consists of transferring freight from depots to intermediate facilities (i.e., Urban Consolidation Centers), while the second echelon consists of transferring freight from these facilities to the final customers, within their time windows.

To our knowledge, only a limited number of studies exist in the literature which consider this problem and propose exact and heuristic solution approaches for the problem. These studies mostly focus on the routing aspect without considering time windows and the ones which consider time windows are mostly solved using (meta)heuristics. This paper considers models with hard time windows at the finnal customers.

More information on this paper, please contact me directly. All test instances are available on this website as well.