Impact of travel time uncertainties on the solution cost of a two-echelon vehicle routing problem with synchronization

Alexandra Anderluh,Pamela C Nolz,Vera C Hemmelmayr,Rune Larsen

doi:10.1007/s10696-019-09351-w

Abstract

Two-echelon vehicle routing problems which contain synchronization between vehicles can be deeply impacted by time uncertainty, because one vehicle’s delay can propagate to other vehicles. In this paper, we evaluate the deterministic solution of such a problem based on simulated travel time scenarios. The information obtained by simulation is incorporated in the optimization procedure iteratively. Computational results show that the degree of synchronization in an instance is directly correlated with the potential improvements by reoptimization. We present findings on the number of travel time scenarios required to obtain a representative picture of the stochastic solutions. In addition, we demonstrate that time dependent travel times can be aggregated on a city-wide level and linearized as a function of free flow times without major loss of reliability.

Highlights

Emission-free, agile vehicles are increasingly used for freight deliveries within cities and especially within historic city centers
The aim of this paper is to investigate the impact of stochastic travel times on the cost of a deterministic solution of a two-echelon vehicle routing problem (2eVRP) with spatial and temporal synchronization
In this paper we analyze the performance of an innovative city distribution scheme for a two-echelon vehicle routing problem with temporal and spatial synchronization between vans and cargo bikes in a realistic setting

Summary

Introduction

Emission-free, agile vehicles are increasingly used for freight deliveries within cities and especially within historic city centers. This development is triggered by the ongoing urbanization as well as the negative effects of climate change caused by greenhouse gas emissions. Negative health effects in cities caused by other transport-related emissions (WHO 2016) contribute to this trend. Innovative logistic concepts are required to enable the efficient use of these vehicles within a distribution network. Either consolidation centers near the city center are required, where those vehicles can reload goods (Quak et al 2014), or a reorganized distribution scheme with synchronization between different types of vehicles can be used to allow for reloading

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