François Combes

• PhD
• Principal Investigator at Gustave Eiffel University

Supply Chains (SFSCs) operate under specific regulatory frameworks, involving either direct sales or transactions with no more than one intermediary. SFSCs are of particular interest to local communities as they offer a potential pathway to enhancing food security through the local provisioning of urban areas. This study investigates both consumers...

Our progress on climate action is too slow, the window is closing fast and an urgent and transformational change is required to stay within the temperature ranges defined by the Paris Climate Agreement The problem cannot be addressed by a simple juxtaposition of solutions emerging from a mitigation-focused, siloed approach or by a straightforward a...

Truck platooning is a technology allowing trucks to travel in convoy formation using wireless communications and advanced driver assistance systems. This technology is expected to increase road safety and capacity, and to decrease fuel consumption and GHG emissions; it comes with apparently important financial benefits and positive externalities. H...

The report combines a wide variety of sources to give orders of magnitudes of warehousing costs and handling costs and, when possible, to analyse the share of land rents in warehousing costs.

Le Smart Lab LABILITY, laboratoire de recherche et d'innovation éphémère, réunit des jeunes chercheurs engagés par l'Université Gustave Eiffel qui analysent l'impact de la crise sanitaire sur l'organisation du travail et sur l'évolution de la mobilité des personnes et des marchandises dans la région francilienne.

Freight transport is one of the most polluting sectors worldwide. While many solutions have been developed for urban logistics-which is the most polluting part of the transport chain-long-distance transport, via trucks, is a major issue for decarbonization. In this study we propose to study the possibility for a major player in the parcel industry...

Urban logistics is a key step in distribution chains. It implies the use of trucks in congested areas, and generates numerous externalities (congestion, noise, pollution, etc.). Supply chain configurations and consumer behaviors are undergoing deep changes, with a significant increase in the intensity of urban logistics and a diversification of del...

Freight transport demand models are generally based on administrative commodity type segmentation which are usually not tailored to behavioral freight transport demand modelling. Recent literature has explored new approaches to segment freight transport demand, notably based on latent class analysis, with promising results. In particular, empirical...

Urban logistics is a key step of distribution chains. It implies the use of trucks in congested areas, and generates numerous externalities (congestion, noise, pollution, etc.). In addition, supply chain configurations and consumer behaviors are undergoing deep changes. This implies a significant increase urban logistics’ intensity, and a diversifi...

Truck platooning is a technology where trucks are coupled in virtual platoons on open roads. This coupling allows to reduce the distance between trucks in a platoon, which leads to fuel savings for the leader and follower vehicles. This presentation is focused on the issue of the market uptake of platooning. This is a complex topic: first, assuming...

Having remained stable at around 18% between 1990 and 2000, the share of rail in freight transport has steadily declined since 2010 to around 10%. At the same time, two recovery plans and strategies, launched in 2009 and 2016, have set ambitious targets, 25% in 2022 and 20% in 2030 respectively. The most recent 2019 strategic law on mobility, in it...

L’objectif de cet article est de fournir quelques éclairages sur le sujet du report modal en transport de marchandises. Il procède en trois parties. Dans un premier temps, la gestion des chaînes logistiques par les chargeurs est expliquée et illustrée par quelques exemples : comment gèrent-ils leurs flux et leurs stocks ? Quelle est influence des c...

This paper presents an overview of changes expected in the role of LCV's in Urban Logistics due to technological changes. It is divided into the following sections; Urban population and logistics; Light commercial vehicles and their use in urban logistics; Transition to Autonomous, Connected, Electric and Shared (AECS); and Regulation of vehicles....

The objective is to study the impact the deployment of autonomous vehicles may have on freight and logistics from an economic point of view. We focus on interurban transport operations made by road and propose quantitative estimations of the outcomes of two scenarios where the automation technology is sufficiently efficient to remove the need of a...

City Logistics is characterized by multiple stakeholders that often have different views on such a complex system. From a public policy perspective, identifying stakeholders, issues and trends is a daunting challenge, only partially addressed by traditional observation systems. Nowadays, social media is one of the biggest channels of public express...

Le transport de marchandises est une activité économique essentielle. La structure des tissus économiques et industriels français et mondiaux implique des mouvements importants de marchandises; la performance du transport de marchandises est donc un facteur important de performance économique. Cependant, il génère plusieurs impacts négatifs (réchau...

Ce rapport a pour objectif de présenter diverses recommandations concernant l'évaluation socio-économique de projets routiers. En particulier, les sujets suivants sont traités: analyse stratégique, étude de trafic, analyse coût-bénéfice, prise en compte des incertitudes.

City Logistics is characterized by multiple stakeholders that often have different views of such a complex system. From a public policy perspective, identifying stakeholders, issues and trends is a daunting challenge, only partially addressed by traditional observation systems. Nowadays, social media is one of the biggest channels of public express...

City Logistics is characterized by multiple stakeholders that often have different views of such a complex system. From a public policy perspective, identifying stakeholders, issues and trends is a daunting challenge, only partially addressed by traditional observation systems. Nowadays, social media is one of the biggest channels of public express...

This is the presentation of the paper "UNSUPERVISED MACHINE LEARNING TO ANALYSE CITY LOGISTICS THROUGH TWITTER" at the 11th International Conference on City Logistics on 12th – 14th June 2019 in Dubrovnik, Croatia. Abstract: City Logistics is characterized by multiple stakeholders that often have different views of such a complex system. From a pub...

Road freight transport is an essential economic activity. It currently relies on the following resources : infrastructure, vehicles, workforce, and energy. If trucks are partially or totally autonomous, the cost structure of freight transport will change substantially. The cost structure of freight transport will change; freight carriers will reorg...

This paper presents a structural microeconomic model of the choice of warehouse location in urban logistics. The model is theoretical and analytical. It brings the focus on operational constraints, their diversity, and their influence on costs. The location decision is modeled as a trade-off between land rents (making it costly to locate close to t...

This paper presents a structural microeconomic model of the choice of warehouse location in urban logistics. The model is theoretical and analytical. It brings the focus on operational constraints, their diversity, and their influence on costs. The location decision is modelled as a trade off between land rents (making it costly to locate close to...

Ce document constitue le « rapport descriptif » des scénarios de décarbonation profonde du transport de marchandises en France à l’horizon 2050. Il s’adresse aux différents acteurs de la société qui souhaiteraient découvrir deux histoires cohérentes des principales transformations (sociétales, organisationnelles, technologiques et politiques) menan...

Transferability is seen as one important rationale for justifying the application of behavioral transport demand models. Concerning freight transportation, behavioral models of shipment size choice gain more and more attention by modelers. However, the transferability of prevalent shipment size choice models is complicated due to different function...

The heterogeneity of supply chains is an important challenge for analysing, understanding and modelling freight transport systems. This paper explores a solution based on a Total Logistics Cost approach and Latent Class Analysis in order to introduce efficiently (i.e. without adding too many degrees of freedom) relevant information in models of cho...

The paper’s objective is to assess the external costs of urban freight transport while taking into account the interaction between passenger transport and freight transport. The paper applies an aggregate approach: an urban freight generation and distribution model (FRETURB) and a passenger trafic model (NODUS) are combined in order to calculate th...

This paper analyses with an analytical microeconomic model how warehouse location depends on the other economic parameters of urban logistics, such as transport cost, freight demand, and rents. In the model, a warehouse located at the outskirts of a city dispatches trucks towards the city center in order to deliver and pickup commodities. A logisti...

In passenger transport, hub-and-spoke networks allow the transportation of small passenger flows with competitive frequencies, in a way that direct line networks cannot. Equivalently, in freight transport, it can be expected that small shipper-receiver flows of high added value commodities transit through hub and spoke networks, while larger shippe...

Consider a population of agents who choose one among a set of destinations located along a rectilinear road. Each of these destinations has a certain utility, modeled by a random variable. We compare a situation where the agents have to explore the destinations to observe the value of their utilities, to a situation where they know these values bef...

This study estimates a disaggregate freight generation model with the French shipper survey ECHO. This survey contains accurate information about French shippers, with variables describing their economic activity, the diversity of their production, their relationships with their clients and carriers, etc. These variables and their influence on prod...

This article presents an empirical analysis of the prices' structure in the road freight industry. For that purpose, we use the French ECHO survey that provides detailed information on the characteristics of shippers and transport operators. First, we show that road freight prices are not a simple linear function of ship-ments' attributes. Second,...

L’usage au quotidien des technologies de l’information et de la communication (TIC) au cours des déplacements — non seulement de personnes, mais également de marchandises — engendre des quantités importantes de données à la fois identifiées, datées et localisées. C’est le cas notamment des systèmes de billettique dans les transports en commun, des...

Inventory theory is concerned with the optimal operation of production, logistics, transport, etc. It can prove particularly useful to freight transport modelling. Indeed, analysing inventory theoretic models from a microeconomic perspective explains a lot about the preferences of shippers regarding freight transport. This chapter reminds some simp...

Inventory theory offers many options to better understand and model the behaviour of shippers and carriers in freight transportation. This includes the choice of shipment size, the choice of vehicle type and the choice of transport mode. This document discusses how some models of inventory theory constitute a sound basis to extend freight transport...

A model of freight mode choice was developed on the basis of the economic order quantity model, an inventory theoretical model of optimal shipment size. Shipment size is not explicit in the mode choice model; however, the specifications of the utilities associated with each transport mode account for shipment size and transport mode, which are two...

The objective of this paper is to analyse in detail the structure of road freight tariffs. To do so, a market equilibrium model is designed, with a detailed representation of the technology of carriers, and of the logistic decisions of shippers. In particular, shippers send shipments of endogenous sizes, which are consolidated by carriers in vehicl...

This paper shows that the particular conditions under which a cellular phone network is operated underground can make it possible to measure passenger flows in an underground transit system. With the help of the mobile network operator Orange, some experiments have been conducted in Paris underground transit system to assess the potential of this n...

This paper shows that the particular conditions in which a cellular phone network is operated underground can make it capture a significant part of particular events like entries in tunnels. With the help of the mobile network operator Orange, some experiments have been conducted in Paris’ underground transit system. Results show that good estimate...

In densely urbanised areas the structure of the transport systems becomes quite complicated. Many types of transport services are available and many types of modes are being used, thus offering a wide palette of transport options. How do all these transport services and modes relate to each other? In practice it proves to he quite hard to define su...

Along a transit line, vehicle traffic and passenger traffic are jointly subject to variability in travel time and vehicle load hence crowding. The paper provides a stochastic model of passenger physical time and generalized time, including waiting on platform and in-vehicle run time from access to egress station. Five sources of variability are add...

The choice of shipment size in freight transport depends on the logistical imperatives of shippers and the technical possibilities of carriers. The choice is closely related to the mode of transportation and therefore important for public policy. The theory of optimal shipment size and mode choice is robust. Numerous inventory-theoretical models of...

Purpose The focus of this paper is to enhance our observation and knowledge of interurban road freight transport. It explores some possibilities for improving roadside freight surveys, usually used to gather origin-destination data. Methodology To achieve this, new questions are added to a standard roadside survey form, and the enhanced survey for...

The value of time, in freight transport, comes from how supply chains work. This chapter discusses this matter and some implications including the endogenous nature of the value of time.

The paper presents a theory of the value of time in freight transport based on inventory theory. On the basis of the work of Arrow et al. (1958) and Baumol and Vinod (1970), the paper derives a model of the willingness of a shipper to pay for a reduction of the transport leadtime in the case of a simple supply chain, where the demand is random, but...

We set a framework where an individual has to choose one among a set of spatially distributed activities. The individual knows the price of each activity, as well as the distance to reach it. She has either full or zero information about each activity's quality. Qualities are modeled by i.i.d. random variables. Under the full information regime, th...

Classic spatialised freight transport models are based on a four stage representation of the decisions shippers and carriers take. The decisions this representation distinguishes are: emitted and received flow rates, supplier or receiver choice, transport mode, itinerary. However, freight transport is discrete by nature: commodities are moved by bu...

Classic spatialised freight transport models are based on a four stage representation of the decisions shippers and carriers take. The decisions this representation distinguishes are: emitted and received flow rates, supplier or receiver choice, transport mode, itinerary. However, freight transport is discrete by nature: commodities are moved by bu...

Numeric, spatialised models for the simulation of freight transport demand have long been inspired by the models for passenger demand. However, in recent years, specific methods have been developped to represent some aspects that are specific to freight transport, including the relationship between freight transport and logistics, and the specific...