Two-echelon urban deliveries using autonomous vehicles

We introduce a two-echelon urban delivery problem with second-level unmanned vehicles. This problem typically applies for delivering parcels or other small commodities to pedestrianized areas such as campuses or residential clusters. To model the proposed vehicle routing problem, we introduce a mixed-integer program. We further propose construction heuristics and a hybrid metaheuristic approach with backtracking for solving larger instances. A sensitivity analysis for vehicle speed combinations reveals that increasing small autonomous vehicle (SAV) speeds has only very limited effects on cost. We therefore recommend to keep SAV speeds rather low because of a more pedestrian friendly environment in practical implementations.