2018 Optimization Days
HEC Montréal, Québec, Canada, 7 — 9 May 2018
WA2 Green routing
May 9, 2018 10:30 AM – 12:10 PM
Location: Banque Scotia (69)
Chaired by Samuel Pelletier
3 Presentations
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10:30 AM - 10:55 AM
Leverage the long recharging times of electric vehicles in city logistics
Electric Vehicle usage represents environmental and economic benefits. Here a variant of e-VRP is studied. We allow visiting a customer by walking while the vehicle is charged. A hybrid-ILS is tested on literature instances: the total recharging time is reduced up to 2.5% and the total distance up to 2.8%.
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10:55 AM - 11:20 AM
Measuring emissions in vehicle routing: new emission estimation models using supervised learning
Based on real-world data of instantaneous fuel consumption, time-varying speeds observations, and traffic data related to a large set of shipping operations, we propose effective methods to estimate greenhouse gas (GHG) emissions. By carrying out nonlinear regression analysis using supervised learning methods, namely Neural Networks, Support Vector Machines, Conditional Inference Trees, and Gradient Boosting Machines, we develop new emission models that provide more prediction accuracy than classical models. Extensive computational experiments under real datasets show the effectiveness of the proposed machine learning emissions models, clearly outperforming the Comprehensive Modal Emissions Model (CMEM) and the Methodology for Estimating air pollutant Emissions from Transport (MEET) in the prediction of hot running traffic emissions according to root mean square error metrics. Based on performance indicators we show that MEET underestimates real-world GHG emissions by 24.94% and CMEM leads to an overestimation of emissions by 13.18% according to observed fuel consumption, while our best machine learning model (Gradient Boosting Machines) exhibited superior estimation accuracy and is off by only 1.70% considering real-world driving conditions.
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11:20 AM - 11:45 AM
The electric vehicle routing problem with energy consumption uncertainty
In urban environments, freight electric vehicles (EVs) are often exclusively charged at a central depot. We therefore introduce the EV routing problem with energy consumption uncertainty, in which EVs must be routed so that no vehicle ends up stranded even in the worst-case energy consumption scenario. We solve small instances using robust optimization techniques, and we propose a metaheuristic to solve large instances.