Goods transportation by the French National Railway (SNCF): The measurement and marketing of reliability

Rail transportation that is timely and dependable can compete with the trucking mode for Just-In-Time (JIT) deliveries. SNCF, the French National Railway, has a number of such offerings that emphasize reliability of freight shipments. We describe several of these SNCF products. They have in common the nature of regularly-scheduled service: planned connections to specific trains at classification yards. We discuss ways that SNCF can measure reliability, monitor it, and market it. Third-party logistics services of the SNCF are summarized, as is marketing research by SNCF to update their product line in goods transportation. We conclude with possibilities for future research.     

An environmental economic analysis of the new rail link to European main port Rotterdam

After a long policy debate it has been decided to built in the near future a new rail link (Betuwe line) in the Netherlands to handle the rapidly increasing volume of goods to be transported from Rotterdam harbour to the centre of Europe. This study analyses its economic and environmental aspects and compares rail transport with road transport and transport on inland waterways. It is shown that transport by water will compete strongly with transport on the new railway and that water transport is attractive economically and environmentally.     

Understanding the impact of e-commerce on last-mile light goods vehicle activity in urban areas: The case of London

Growth in e-commerce has led to increasing use of light goods vehicles for parcel deliveries in urban areas. This paper provides an insight into the reasons behind this growth and the resulting effort required to meet the exacting delivery services offered by e-retailers which often lead to poor vehicle utilisation in the last-mile operation, as well as the duplication of delivery services in urban centres as competitors vie for business. A case study investigating current parcel delivery operations in central London identified the scale of the challenge facing the last-mile parcel delivery driver, highlighting the importance of walking which can account for 62% of the total vehicle round time and 40% of the total round distance in the operations studied. The characteristics of these operations are in direct conflict with the urban infrastructure which is being increasingly redesigned in favour of walking, cycling and public transport, reducing the kerbside accessibility for last-mile operations. The paper highlights other pressures on last-mile operators associated with managing seasonal peaks in demand; reduced lead times between customers placing orders and deliveries being made; meeting delivery time windows; first-time delivery failure rates and the need to manage high levels of product returns. It concludes by describing a range of initiatives that retailers and parcel carriers, sometimes in conjunction with city authorities, can implement to reduce the costs associated with last-mile delivery, without negatively impacting on customer service levels.     

A heuristic for the train pathing and timetabling problem

In a railroad system, train pathing is concerned with the assignment of trains to links and tracks, and train timetabling allocates time slots to trains. These important tasks were traditionally done manually, but there is an increasing move toward automated software based on mathematical models and algorithms. Most published models in the literature either focus on train timetabling only, or are too complicated to solve when facing large instances. In this paper, we present an optimization heuristic that includes both train pathing and train timetabling, and has the ability to solve real-sized instances. This heuristic allows the operation time of trains to depend on the assigned track, and also lets the minimum headway between the trains to depend on the trains’ relative status. It generates an initial solution with a simple rule, and then uses a four-step process to derive the solution iteratively. Each iteration starts by altering the order the trains travel between stations, then it assigns the services to the tracks in the stations with a binary integer program, determines the order they pass through the stations with a linear program, and uses another linear program to produce a timetable. After these four steps, the heuristic accepts or rejects the new solution according to a Threshold Accepting rule. By decomposing the original complex problem into four parts, and by attacking each part with simpler neighborhood-search processes or mathematical programs, the heuristic is able to solve realistic instances. When tested with two real-world examples, one from a 159.3 km, 29-station railroad that offers 44 daily services, and another from a 345 km, eight-station high-speed rail with 128 services, the heuristic obtained timetables that are at least as good as real schedules.     

Positive impact of distribution centres on the environment

The transport sector in general, and trucks in particular, generates a significant amount of emissions in Australia. It appears the trend will escalate unless different measures are taken to reduce the reliance of freight transport on trucks. This paper discusses the benefits of distribution centres as a means to reduce road congestion, increase safety, protect the environment by reducing atmospheric pollution and improve freight distribution. It also provides the effective use of the existing rail network and its infrastructure and improves the lead-time as well as lowering the cost of transportation of cargo. It also investigates the positive impact of distribution centres located near to manufacturing and farming production units. A simulation model has been developed and used to help determine the amount of atmospheric pollution produced by two modes of land transport, rail and road, for the movement of containers between port and destination. Results derived from the model provide evidence about a preferred land-transport regime. The paper has two sections: (1) the role of distribution centres in the chain of transport and (2) the impact of distribution centres on the environment. The first section investigates the feasibility of the implementation of distribution centres in the State of Victoria with respect to rail line capacity and location allocation. The second section presents an additional simulation model that investigates the role of a distribution centre in relation to the amount of atmospheric pollution produced by rail and road, while containers are carried between port and destination.     

A new shared vehicle system for urban areas

The paper concerns the conceptual design of a transport system for pedestrian areas. The proposed transport system is based on a fleet of eco-sustainable Personal Intelligent City Accessible Vehicles (PICAVs). The vehicles are shared through the day by different users and the following specific services will be provided: instant access, open ended reservation and one way trips. Referring to the proposed transport system, a new methodology to optimise the fleet dimension and its distribution among the stations is proposed in this paper. The problem faced is an optimisation problem where the cost function to be minimised takes into account both the transport system cost and the user costs that depend on the waiting times. A random search algorithm has been adopted. Given a fleet dimension and its distribution among the stations, the waiting times of the users are assessed by a microscopic simulation. The simulation model tracks the second-by-second activity of each PICAV user, as well as the second-by-second activity of each vehicle. The overall methodology has been implemented in an object-oriented simulator. The proposed transport system has been planned and simulated for the historical city centre of Genoa, Italy.     

Coordinated cruise control for high-speed train movements based on a multi-agent model

This paper investigates the coordinated cruise control strategy for multiple high-speed trains’ movement. The motion of an ordered set of high-speed trains running on a railway line is modeled by a multi-agent system, in which each train communicates with its neighboring trains to adjust its speed. By using the potential fields and LaSalles invariance principle, we design a new coordinated cruise control strategy for each train based on the neighboring trains’ information, under which each train can track the desired speed, and the headway distances between any two neighboring trains are stabilized in a safety range. Numerical examples are given to illustrate the effectiveness of the proposed methods.     

A dynamic lane-changing trajectory planning model for automated vehicles

This paper focuses on the lane-changing trajectory planning (LTP) process in the automatic driving technologies. Existing studies on the LTP algorithms are primarily the static planning method in which the states of the surrounding vehicles of a lane-changing vehicle are assumed to keep unchanged in the whole lane-changing process. However, in real-world traffic, the velocities of the surrounding vehicles change dynamically, and the lane-changing vehicle needs to adjust its velocity and positions correspondingly in real-time to maintain safety. To address such limitations, the dynamic lane-changing trajectory planning (DLTP) model is proposed in the limited literature. This paper proposes a novel DLTP model consisting of the lane-changing starting-point determination module, trajectory decision module and trajectory generation module. The model adopts a time-independent polynomial trajectory curve to avoid the unrealistic assumptions on lane-changing velocities and accelerations in the existing DLTP model. Moreover, a rollover-avoidance algorithm and a collision-avoidance algorithm containing a reaction time are presented to guarantee the lane-changing safety of automated vehicles, even in an emergent braking situation. The field lane-changing data from NGSIM data are used to construct a real traffic environment for lane-changing vehicles and verify the effectiveness of the proposed model, and CarSim is applied to investigate the traceability of the planned lane-changing trajectories using the proposed model. The results indicate that an automated vehicle can complete the lane-changing process smoothly, efficiently and safely following the trajectory planned by the proposed model, and the planned velocity and trajectory can be well-tracked by automated vehicles.     

The environmental impact of distribution to retail channels: A case study on packaged beverages

This study aims to quantify the environmental impact of two retail distribution networks and offer consumers a channel that is more beneficial to the environment. The environmental impact of replenishing the packaged beverages sold in convenience stores (CVSs) and hypermarkets is assessed using the streamlined life-cycle assessment (LCA) approach. In this study, the life-cycle impact assessment (LCIA) for packaged beverages up to the point of sale illustrates the distribution-level environmental impacts of truck transportation. The matched-pair t-test shows that the environmental impacts of transporting 1800 cartons of 24-pack/10 oz. beverages to be sold in Carrefour and 7-11 stores is different at a significance level of 0.1. The transport-focused LCA is used to improve the understanding and compare the environmental characteristics of the two distribution and retail systems. This study constitutes a vehicle for communicating to both internal and external stakeholders the environmental profiles of distributing the same product sold through two retail channels.     

Design of multiple-vehicle delivery tours—III valuable goods

For the delivery of valuable goods (such as people in a van pool), we assume that it costs c_v per unit time during a round trip time of a vehicle and it costs c_u/C per unit time for each of C items being delivered only during the travel time from the source to the point of delivery. The objective is to design delivery routes so as to minimize the (expected) total cost of delivery in some region containing N ⪢ C delivery points. With nearly rectangular shaped delivery zones for each vehicle route it is shown that if c_u/2 < c_v, one should use essentially the same strategy as described in Parts I and II. In each delivery zone one should deliver to approximately half the points on the outbound leg of the route and the other half on the return. For c_u/2 > c_v, however, one should deliver only on the outbound leg and deadhead back from the far end of the zone. In each case there is an optimal width and orientation of the rectangular zone relative to the local grid of roads and the travel-time contours from the source.     

Cost analysis for high-volume and long-haul transportation of densified biomass feedstock

Using densified biomass to produce biofuels has the potential to reduce the cost of delivering biomass to biorefineries. Densified biomass has physical properties similar to grain, and therefore, the transportation system in support of delivering densified biomass to a biorenery is expected to emulate the current grain transportation system. By analyzing transportation costs for products like grain and woodchips, this paper identifies the main factors that impact the delivery cost of densified biomass and quantifies those factors’ impact on transportation costs. This paper provides a transportation-cost analysis which will aid the design and management of biofuel supply chains. This evaluation is very important because the expensive logistics and transportation costs are one of the major barriers slowing development in this industry.Regression analysis indicates that transportation costs for densified biomass will be impacted by transportation distance, volume shipped, transportation mode used, and shipment destination, just to name a few. Since biomass production is concentrated in the Midwestern United States, a biorefinery’s shipments will probably come from that region. For shipments from the Midwest to the Southeast US, barge transportation, if available, is the least expensive transportation mode. If barge is not available, then unit trains are the least expensive mode for distances longer than 161 km (100 miles). For shipments from the Midwest to the West US, unit trains are the least expensive transportation mode for distances over 338 km (210 miles). For shorter distances, truck is the least expensive transportation mode for densified biomass.     

Emissions of particulate matters from railways – Emission factors and condition monitoring

We report tunnel measurements, where abrasion particles from different types of trains are measured in two situations and emission factors are calculated from these. The measurements show significantly elevated particle concentrations in train passages that last for about a minute and are accompanied by increased airflow. The emission of particles for each train passage was obtained by summing the product of the particle concentration and the airflow and then multiplying with the tunnel area. The average emission factors were calculated for three categories freight trains, commuter trains and regional trains and found to be 2.9 g/train-km (0.7 – 9), 0.48 (0.1 – 1.6) and 0.24 (0.05–0.9), respectively. The number in brackets refers to the range of values observed. The size-resolved data showed maxima around 1 μm for all three train types.     

Scheduling freight trains traveling on complex networks

In the US, freight railways are one of the major means to transport goods from ports to inland destinations. According to the Association of American Railroad’s study, rail companies move more than 40% of the nation’s total freight. Given the fact that the freight railway industry is already running without much excess capacity, better planning and scheduling tools are needed to effectively manage the scarce resources, in order to cope with the rapidly increasing demand for railway transportation. This research develops optimization-based approaches for scheduling of freight trains. Two mathematical formulations of the scheduling problem are first introduced. One assumes the path of each train, which is the track segments each train uses, is given and the other one relaxes this assumption. Several heuristics based on mixtures of the two formulations are proposed. The proposed algorithms are able to outperform two existing heuristics, namely a simple look-ahead greedy heuristic and a global neighborhood search algorithm, in terms of railway total train delay. For large networks, two algorithms based on the idea of decomposition are developed and are shown to significantly outperform two existing algorithms.     

Automated cars: Queue discharge at signalized intersections with ‘Assured-Clear-Distance-Ahead’ driving strategies

This study addresses the impacts of automated cars on traffic flow at signalized intersections. We develop and subsequently employ a deterministic simulation model of the kinematics of automated cars at a signalized intersection approach, when proceeding forward from a stationary queue at the beginning of a signal phase. In the discrete-time simulation, each vehicle pursues an operational strategy that is consistent with the ‘Assured Clear Distance Ahead’ criterion: each vehicle limits its speed and spacing from the vehicle ahead of it by its objective of not striking it, regardless of whether or not the future behavior of the vehicle ahead is cooperative. The simulation incorporates a set of assumptions regarding the values of operational parameters that will govern automated cars’ kinematics in the immediate future, which are sourced from the relevant literature.We report several findings of note. First, under a set of assumed ‘central’ (i.e. most plausible) parameter values, the time requirement to process a standing queue of ten vehicles is decreased by 25% relative to human driven vehicles. Second, it was found that the standard queue discharge model for human–driven cars does not directly transfer to queue discharge of automated vehicles. Third, a wet roadway surface may result in an increase in capacity at signalized intersections. Fourth, a specific form of vehicle-to-vehicle (V2V) communications that allows all automated vehicles in the stationary queue to begin moving simultaneously at the beginning of a signal phase provides relatively minor increases in capacity in this analysis. Fifth, in recognition of uncertainty regarding the value of each operational parameter, we identify (via scenario analysis, calculation of arc elasticities, and Monte-Carlo methods) the relative sensitivity of overall traffic flow efficiency to the value of each operational parameter.This study comprises an incremental step towards the broader objective of adapting standard techniques for analyzing traffic operations to account for the capabilities of automated vehicles.     

Automated shunting of rail container wagons in ports and terminal areas

The development of intermodal container transport is hampered in part by the cost associated with the shunting of trains in marshalling yards, inland and port railway terminals. Many new technologies have been developed in the past decade, but have still not been applied because of high capital investment costs, lack of sufficient market demand and uncertain rates of return. The key for increasing the competitiveness of intermodal container transport by rail is the operation of heavy haul container trains between port and inland railway terminals more frequently with fast, flexible and automatic transhipment, shunting and coupling of container wagons. The operation of self-driven railcars equipped with automatic centre coupling on terminal tracks, which can also be train-hauled on conventional hinterland railway lines, would enable a reduction of shunting and transhipment time and costs in intermodal container terminals by more than 30%.     

Mining missing train logs from Smart Card data

This paper shows how to recover the arrival times of trains from the gate times of metro passengers from Smart Card data. Such technique is essential when a log, the set of records indicating the actual arrival and departure time of each bus or train at each station and also a critical component in reliability analysis of a transportation system, is missing partially or entirely. The procedure reconstructs each train as a sequence of the earliest exit times, called S-epochs, among its alighting passengers at each stations. The procedure first constructs a set of passengers, also known as reference passengers, whose routing choices are easily identifiable. The procedure then computes, from the exit times of the reference passengers, a set of tentative S-epochs based on a detection measure whose validity relies on an extreme-value characteristic of the platform-to-gate movement of alighting passengers. The tentative S-epochs are then finalized to be a true one, or rejected, based on their consistencies with bounds and/or interpolation from prescribed S-epochs of adjacent trains and stations. Tested on 12 daily sets of trains, with varying degrees of missing logs, from three entire metro lines, the method restored the arrival times of 95% of trains within the error of 24 s even when 100% of logs was missing. The mining procedure can also be applied to trains operating under special strategies such as short-turning and skip-stop. The recovered log seems precise enough for the current reliability analysis performed by the city of Seoul.     

Solving the User Optimum Privately Owned Automated Vehicles Assignment Problem (UO-POAVAP): A model to explore the impacts of self-driving vehicles on urban mobility

Interest in vehicle automation has been growing in recent years, especially with the very visible Google car project. Although full automation is not yet a reality there has been significant research on the impacts of self-driving vehicles on traffic flows, mainly on interurban roads. However, little attention has been given to what could happen to urban mobility when all vehicles are automated. In this paper we propose a new method to study how replacing privately owned conventional vehicles with automated ones affects traffic delays and parking demand in a city. The model solves what we designate as the User Optimum Privately Owned Automated Vehicles Assignment Problem (UO-POAVAP), which dynamically assigns family trips in their automated vehicles in an urban road network from a user equilibrium perspective where, in equilibrium, households with similar trips should have similar transport costs. Automation allows a vehicle to travel without passengers to satisfy multiple household trips and, if needed, to park itself in any of the network nodes to benefit from lower parking charges. Nonetheless, the empty trips can also represent added congestion in the network. The model was applied to a case study based on the city of Delft, the Netherlands. Several experiments were done, comparing scenarios where parking policies and value of travel time (VTT) are changed. The model shows good equilibrium convergence with a small difference between the general costs of traveling for similar families. We were able to conclude that vehicle automation reduces generalized transport costs, satisfies more trips by car and is associated with increased traffic congestion because empty vehicles have to be relocated. It is possible for a city to charge for all street parking and create free central parking lots that will keep total transport costs the same, or reduce them. However, this will add to congestion as traffic competes to access those central nodes. In a scenario where a lower VTT is experienced by the travelers, because of the added comfort of vehicle automation, the car mode share increases. Nevertheless this may help to reduce traffic congestion because some vehicles will reroute to satisfy trips which previously were not cost efficient to be done by car. Placing the free parking in the outskirts is less attractive due to the extra kilometers but with a lower VTT the same private vehicle demand would be attended with the advantage of freeing space in the city center.     

Transportation Risk ANalysis tool for hazardous Substances (TRANS) – A user-friendly,semi-quantitative multi-mode hazmat transport route safety risk estimation methodology for Flanders

The paper develops a methodology for assessing the relative risk levels in moving hazardous materials by various transport modes. Transportation Risk ANalysis tool for hazardous Substances (TRANS) divides routes into smaller segments using multi-criteria analysis and likelihood scores of accidents in which dangerous cargoes are involved possibly causing fatalities. The consequences of accident scenarios are calculated in terms of the number of people within 1% of the lethal distance from the accident centre. This provides a user-friendly, semi-quantitative risk analysis tool. The generic method allows for comparing the risk levels of the segments of routes used in the transportation of hazardous goods.     

Robust stop-skipping patterns in urban railway operations under traffic alteration situation

In this paper an operation mode which is based on the stop-skipping approach is studied in urban railway lines under uncertainty. In this mode, each train follows a specific stop schedule. Trains are allowed to skip any intermediate stations to increase the commercial speed and to save energy consumption. As the commercial speed increases, the number of required trains in operation reduces and results eliminating unnecessary costs. To that end, a new mathematical model is proposed to reach the optimum stop schedule patterns. In the planning step, based on the traffic studies, the headway distributions are computed for different weekdays, and holidays. However, in practice, because of many unexpected events, the traffic may alter from what is planned. Therefore, in this condition, a robust plan is required that is optimized and immunized from uncertainty. In this paper, a new robust mathematical model, as well as two heuristic algorithms including (1) a decomposition-based algorithm and (2) a Simulated Annealing (SA) based algorithm is proposed. Finally, an Iranian metro line is studied and the optimum patterns are presented and analyzed.