Impacts on modal choices of new generation freights terminals

Increasing pollution, congestion of roads and worries about the spatial and environmental impacts of road transports have promoted the idea of transferring part of freight transportation from roads to railways and waterways. Given the limited density of these two modes' networks, this policy implies necessarily the development of inter-modal transports. But their operation on a large scale is meeting several problems : the additional cost of transferring the commodities from one mode or means to another, the size of investments in new technology equipment for terminals, specialized rolling stock and information systems, the involvement of several intermediaries plus the control and management of safety and reliability of the services. In the past, many innovative plans and projects for bundling and transshipping were developed, but many plans were abandoned, and despite a steady growth of inter-modal transports, the results obtained are still limited. At the present time, the most promising projects seem to be the introduction of new shuttle connections on transport links with important flows of transports. However, lower costs and better management of services could probably make attractive the organization of more complex schemes like hub-and-spokes organizations. The paper presents a methodology to model bundling concepts on multi-modal freight networks. It is based on the extensive use of virtual links as they are implemented in the NODUS software developed by GTM . Different configurations of inter-modal networks are modeled which are implemented in a digitized trans-European multi-modal network (rail, road and waterway). Cost functions are associated with every (virtual) link which corresponds to a particular transport operation. A matrix of origins and destinations throughout the European space is generated on the basis of global EUROSTAT statistics by the use of a weighted stochastic procedure. Given this transportation task a minimization of generalized costs can be made which assigns transport flows between paths, modes and means of transport. Hence, successive simulations for different configurations and various parameters' values provide a set of measures of their impacts, which can be used for assessing the interest of concrete inter-modal propositions. The indicators are the market shares, the total operating cost of the transportation task, the total cost of a particular operation, the distances covered, the times of transport, the service frequency required, the energy consumption, etc. This research is part of the EU Commission's TERMINET project which focuses on the potentialities of innovative bundling concepts for transport nodes and terminals.

A multicriteria analysis of stated preferences among freight transport alternatives

Stated preferences data can be of different types: choice data, rankings or ratings. In all cases, these data can be used in different ways as inputs of econometric discrete choice models. This allows to estimate the weights of the different attributes characterizing an alternative. For freight transport, an alternative's attributes would be, for example, reliability, safety, frequency, etc., besides time and cost. Depending on the data sample, number of alternatives and number of attributes, it is possible to proceed to an analysis of individual data or of aggregated data. In case one is interested to analyze individual behaviors in depth, the option exists to rely on some kind of multicriteria analysis for deriving individual utility functions (actually, decision functions) rather than on a classic discrete choice model. Such a procedure also can be useful for deriving individual utilities as input in a hybrid model combining individual utilities with group data. Such a multicriteria approach is envisaged in the context of a stated preference experiment that is currently applied to freight shippers in Belgium. The data in this case are rankings of alternatives, and there is multicritera method that is particularly well adapted for such data: the UTA models developed by Jacquet-Lagrèze and Siskos. It is based on the specification of an additive utility made of non-linear partial utility functions that are piecewise linear. This allows the convenient set-up of a linear goal programming problem which estimates all the functions and their weights. The paper intends to present the ranking experiment, and to use some of the preliminary interviews to illustrate this UTA methodology. Also, it will be shown how it can be used to derive equivalent money values for each attributes on the basis of the cost attribute, and how to distinguish valuations in terms of willingness to pay and willingness to accept a compensation.

Methods of Transport Project Evaluation: From cost-benefit to multiciteria and the decision framework

Methods of Transport Project Evaluation: From cost-benefit to multiciteria and the decision framewor

A comment on W. Wei and M. Hansen's benefit estimation in "An aggregate demand model for air passenger traffic in the hub-and-spoke network"

This comment analyzes the demand model and method used by W. Wei and M. Hansen for computing the benefits of an airport capacity extension. The log-linear specification and coefficients of the demand function imply that the airport extension's positive effect on demand decreases with the volume of traffic and associated congestion. If this unlikely result is accepted, the surplus method used by Wei and Hansen underestimates the users' investment benefit. The note argues that the marginal willingness to pay for a capacity extension should rather increase with congestion. If this is the case, the method used by Wei and Hansen could actually overestimates the benefit. A better specification would rather allow for a function concave to the origin in order to account for capacity constraints, and also set a maximum finite price. Above all, a fair evaluation of the users' benefit should be based on a function which explicitly includes a variable, or function of variables, that permits an estimation of the users' cost of congestion. (c) 2008 Elsevier Ltd. All rights reserved

Assessing risky public investments with MUSTARD

This paper presents a practical implementation of multicriteria methodologies based on the UTA model by Jacquet-Lagrèze and Siskos and Quasi-UTA model by Beuthe and Scannella, which are specified with a non-linear, but piecewise linear, additive utility function. In contrast with the general UTA model, the Quasi-UTA specification structures the partial utilities as recursive exponential functions of only one curvature parameter. This allows for a reduction of the quantity of information necessary to build the utility function. The software MUSTARD implements different variants of these models. Firstly, it offers the basic deterministic UTA model of disaggregation, but also its first programmed stochastic version. In both cases, the software proceeds stepwise and interactively helping the decision maker to formulate the problem and state preferences between projects; in the stochastic case, the decision maker is even helped to build the criteria distributions. The Quasi-UTA specification can be introduced in this disaggregation model. Secondly, the software offers an aggregation model whereby the Quasi-UTA partial utility functions are built separately through specific questioning processes. The questions relating to deterministic criteria are of the direct rating type, while those of the stochastic criteria are either of the variable probability or the variable outcome type. The criteria weights can be assessed by the swing weight method or by a UTA-II side-program. As an example as well as a test of the Quasi-UTA aggregation approach, the paper presents its application to a real problem of selecting road investment projects in Belgium. Several experts and civil servants were interviewed, and their individual utility functions derived. The projects are ranked according to their rate of return, which is computed on the basis of the projects certain equivalent money valu

Calcul des bénéfices d'investissements sur un réseau multimodal de transport de marchandises avec congestion

Calcul des bénéfices d'investissements sur un réseau multimodal de transport de marchandises avec congestio