Freight Transportation Planning on the European Multimodal Network: the case of the Walloon Region

This paper presents a methodology that can be used for long-term planning of freight transportation on multimodal networks. It is illustrated by research carried out for the Belgian Walloon Ministry of Transport between 1997 and 1999. Its aim was to provide a tool for measuring the impacts of different kinds of policies and/or new infrastructures on freight transport flows in and through Wallonia. The work started with the setting up of a calibrated multimodal and multi-products reference scenario for the year 1995. This reference scenario was then used as a basis to create a projection for the year 2010: in order to make this projection as realistic as possible, all the decided new infrastructures in Belgium and in the border countries that will be effective in 2010 were introduced in the model. Moreover, expected changes in the O-D matrixes were also introduced at a very detailed level. Then, a set of scenarios was build: one for each transportation mode in which specific changes for that mode were introduced, and one in which the external costs of transport were taken into account. On the basis of the obtained results, a ætransportation planÆ was built, in which the most promising changes in the different networks and policies were chosen. A sensitivity analysis (low and high economic activity) was finally performed

Rail-Road terminal locations: aggregation errors and best potential locations on large networks

In network location problems, the number of potential locations is often too large in order to find a solution in a reasonable computing time. That is why aggregation techniques are often used to reduce the number of nodes. This reduction of the size of the location problems makes them more computationally tractable, but aggregation introduces errors into the solutions. Some of these errors will be estimated in this paper. A method that helps to isolate the best potential locations for rail-road terminals embedded in a hub-and-spoke network will further be outlined. Hub location problems arise when it is desirable to consolidate flows at certain locations called hubs. The basic idea is to use the flows of commodities and their geographic spreading as input to determine a set of potential locations for hub terminals. The exercise will be done for the trans-European networks. These potential locations can then further be used as input by an optimal location method

Carpooling and employers: a multilevel modelling approach

Both public policy-makers and private companies promote carpooling as a commuting alternative in order to reduce the number of Single Occupant Vehicle (SOV) users. The Belgian questionnaire Home-To-Work-Travel (HTWT) is used to examine the factors which explain the share of carpooling employees at a worksite. The modal split between carpooling and rail use was also subject of the analysis. The number of observations in the HTWT database (n=7460) makes it possible to use more advanced statistical models: such as multilevel regression models which incorporate, next to the worksite level, also the company and economic sector levels. As a consequence, a more employer-oriented approach replaces the traditional focus of commuting research on the individual. Significant differences in modal split between economic sectors appeared. The most carpool-oriented sectors are construction and manufacturing, while rail transport is more popular in the financial and public sector. Carpooling also tend to be an alternative at locations where rail is no real alternative. Next to this, regular work schedules and smaller sites are positively correlated with a higher share of carpooling employees. Finally, no real evidence could be found for the effectiveness of mobility management measures which promote carpooling. However, most of these measures are classified in the literature as less effective and a case study approach should complete the research on mobility management initiatives

The DIDAM framework Disaggregated demand and assignment models for combined passengers and freight transport

The objective of this paper is to present the methodological developments in the DIDAM (Disaggregated demand and assignment models for combined passengers and freight transport) research project, which aims at advancing fundamental research in transportation modelling and analysis, using two complementary methodologies. The first is to develop a joint methodological approach for both freight and passenger transport, and the second is to base this common approach on the use of models that are as disaggregate and realistic as possible. Furthermore, the methods will be designed to cope with the important question of competition for infrastructure. The project is mainly organized around two themes. Each of them covers both freight and passengers aspects, in a manner which promotes collaborative work between the partners of the project. The first theme is concerned with disaggregate demand modelling issues, the second deals with innovative aspects of (joint) traffic assignment. Working at a fully disaggregate level is however not always easy. If such models are already available for passenger demand and traffic, disaggregate tools are still largely missing for freight transport. This is not only true at the operational level, but, more crucially, at the conceptual level. This is why our research program adopts, in this domain, a progressive approach that introduces disaggregation gradually into existing methods and models. This entails research in a full spectrum of issues, ranging from concepts definition (who are the actors, how can they be characterized ...) to validation exercises using available data source

“Let the business cycle!” A spatial multilevel analysis of cycling to work

The daily commute is still the main source of traffic congestion. Despite transport research emphasis on commuters, the work end of home to work travel receives less attention. However, employers influence the commute behaviour of employees in different ways. The Belgian database Home-to-Work-Traffic (HTWT) contains information on accessibility, work regimes and mobility management initiatives of 7460 worksites of large employers in Belgium. In a spatial multilevel regression model both contextual and worksite factors are incorporated to investigate the share of cycling employees. While controlling for different economic, physical and other factors, the provision of bicycles by the employer seems to be successful, while the effect of bicycle facilities is less clear, partly due to the fact that bicycle facilities are more popular in less cycle-friendly areas.Het dagelijkse pendelverkeer is nog steeds de voornaamste bron van verkeerscongestie. Ondanks de nadruk die transportonderzoek legt op dit pendelverkeer, blijft de werkkant van het woon-werkverkeer onderbelicht. Nochtans beïnvloeden werkgevers het pendelgedrag van hun werknemers op verschillende manieren. De Belgische databank woon-werkverkeer bevat informatie over de bereikbaarheid, de arbeidstijden en mobility management maatregelen van 7460 werklocaties van grote werkgevers gevestigd in België. In een ruimtelijk multilevel regressiemodel zijn zowel omgevings- als werklocatiefactoren opgenomen om het aandeel fietsende werknemers te verklaren. Rekening houdend met economische, fysische en andere factoren, lijkt het actief aanbieden van fietsen door de werkgever een succesvolle maatregel, terwijl het effect van de klassieke fietsvoorzieningen minder duidelijk is, onder meer omdat deze vooral terug te vinden zijn in minder fietsvriendelijke gebieden

Location and market area of rail-road terminals

The European transport policy has focused on sustainable transport solutions. One of its objectives for freight transport is to restore the balance between modes and to develop intermodality. Among the various types of intermodal transports, this research is concerned with rail-road container terminals embedded in a hub-and–spoke network. These terminals will further be referred to as hubs. Hub-and-spoke networks have been implemented in a number of transportation systems when it is favourable to consolidate and disseminate flows at certain locations called hubs. The efficiency of such a network depends on the location of the hubs. The problem is to find the optimal hub locations and to allocate the remaining nodes to these hubs. This problem is known as the p-hub median problem (p-HMP) where p is the number of hubs to locate. This location-allocation problem is proved to be NP-hard. The time needed to solve it increases as the number of nodes exponent three. Thus, in order to model rail-road transport on the trans-European networks, a subset of nodes that can be considered as good potential locations is needed. We applied the p-HMP to a set of potential locations obtained by both spatial aggregation of demand nodes using hierarchical clustering methods and by a flow-based approach which takes the flows of commodities and their geographic spread into account. They showed that the latest method gives better results and that is why it is retained to determine a set of potential locations. The set of potential locations is used as input for an iterative procedure. One of the main contributions of this research is to propose this iterative procedure based on both the p-HMP and the multi-modal assignment problem. Moreover, the objective function of our p-hub median formulation includes the costs for pre- and post-haulages by road, trans-shipment (according to the number of handled containers into account) and rail haulage. Furthermore, in the p-hub median problem, the total demand is assigned to the hubs. In this research however, the demand can be assigned over all the transportation modes, with the possibility (but not the obligation) of using the trans-shipment facilities. Finally, we presents a methodology able to compare road and rail-road intermodal market areas that takes the network structures, the operation costs and the location of the rail-road terminals into account. This methodology is applied to the optimal configurations obtained by the resolution of the p-HMP and the p-hub centre problem (p-HCP) for the whole trans-European network. Indeed, p-HMP has an efficiency goal by minimizing the total transportation cost. The hub network design obtained by this method can sometimes lead to unsatisfactory results when worst-case origin-destination pairs are separated by a very large distance. Therefore, the p-HCM meets the equity objective by minimizing the maximum cost of a combined transport

Inter-modal freight terminal location in Europe : a strategic model

The political pressure in favour of multi- and inter-modal transport has oriented the focus on sustainable transport solutions. Inter-modal transport is one of the possible solutions, but its efficiency strongly depends on the places where the container terminals are located. The number of possible locations on large scale networks becomes rapidly too large to be taken as input by exact location methods. That’s why the first goal of this paper is to outline a method that helps to identify the best potential locations out of the thousands of potential nodes. The basic idea is to use the flows of commodities and their geographic spreading as input to determine a set of good potential locations for transfer inter-modal terminals. This set can, in a second step, be used as input for already well known optimal location models in order to identify the optimal locations for container terminals in Europe. The methodology is illustrated over the whole trans-European networks. The paper concludes with a discussion of the results: the model predicts a reduction of the total transportation costs on the network and a modal shift from road to rail. It also evaluates the new modal shift and other indicator