Michel Beuthe

FREIGHT TRANSPORTATION DEMAND ELASTICITIES: A GEOGRAPHIC MULTIMODAL TRANSPORTATION NETWORK ANALYSIS

Abstract This paper presents direct and cross-elasticity estimates of the demands for three freight transportation modes: rail, road and inland waterways. They are computed for 10 different categories of goods with a detailed multimodal network model of Belgian freight transports. The model, which minimises the generalised cost of transportation tasks defined by O-D matrices, assigns traffic flows to the different modes, transport means and routes. Successive simulations with different relative costs permit the computation of specific arc-elasticities. In contrast with the usual methodologies, the present methodology is not based on a statistical analysis of disaggregate data on actual modal choices and transport tariffs. This is a particularly useful feature since such data are mostly not available for freight transports in Europe. Furthermore, it fully takes into account the detailed characteristics of the network, all available routes and combinations of modes, as well as the specific localisation of activities within the network. Its estimates are compared with previously published estimates, and, in particular, with Abdelwahabs results published (1998) in this journal.

Comparative Analysis of UTA Multicriteria Methods

Abstract This paper reviews the main variants of the utility additive (UTA) multicriteria method, and systematically compares their predictive performance on two sets of data. It analyses both those cases where the model provides a ranking with errors and those without errors. First, it shows that the reference projects should be chosen carefully in order to elicit as much information as possible from the decision maker: a set of projects satisfying a fractional factorial plan is recommended. Second, it discusses the use of alternative post-optimality methods for solving the problem of multiple solutions and their different predictive performances. Third, it presents the results of simulations based on utility functions involving interdependence between criteria, and shows that UTA handles this problem effectively by an adjustment of its coefficients. Finally, the influence of the models parameters on the predictive performance is also investigated.

TRANSPORTATION POLICY ANALYSIS WITH A GEOGRAPHIC INFORMATION SYSTEM: THE VIRTUAL NETWORK OF FREIGHT TRANSPORTATION IN EUROPE

A multi-modal freight transportation model is presented, based on a digitized geographic network. A systematic analysis and decomposition of all the transport operations leads to the development of a virtual network where each virtual link corresponds to a specific operation, and all transportation modes and means are interlinked. Software, called NODUS, automatically generates the virtual network so that the model can be easily applied to large networks. The analytical structure of the links notation makes it simple to attach specific cost functions to each virtual link. The model is applied to the trans-European freight network for the transportation of wood products. Cost functions are built up for each operation by each mode/means combination. A detailed point-to-point origin-destination matrix, calibrated on Eurostat statistics, is generated by a Monte Carlo technique. The total transportation cost is then minimized with respect to the choices of routes, modes, and means. This provides estimations of transportation services demands as well as modal splits, to the extent that the 2 hypotheses of demand based on generalized cost minimization and market contestability are accepted. A sensitivity analysis on the relative road cost is made, providing measures of arc-elasticities.

Freight bundling network models: methodology and application

Fac Univ Catholiques Mons, Grp Transport & Mobil, B-7000 Mons, Belgium. Limburgs Univ Ctr, B-3590 Diepenbeek, Belgium.Jourquin, B, Fac Univ Catholiques Mons, Grp Transport & Mobil, 151 Ch de Binche, B-7000 Mons, Belgium.

Estimating Freight Transport Price Elasticity in Multi-mode Studies: A Review and Additional Results from a Multimodal Network Model

Abstract The paper presents a detailed comparative review of price/cost elasticity estimates published in a number of studies on multi-mode freight transport demands. It attempts to determine which factors could explain the wide diversity of estimates: data aggregation, diversity of markets, and methodology. It also presents new estimates for rail, road, and waterway modes, derived from a multimodal freight network model of the Rhine area market. Direct and cross-elasticities are estimated for 11 groups of commodities and per distance category. The results are critically assessed by comparison with the reviewed studies. The paper concludes with a few recommendations about meaningful uses of existing estimates and the need for additional experiments with different methodologies applied on a common data basis.

Production uncertainty and the market equilibrium of the competitive firm

Abstract Assumptions Outputs are planned ex ante by risk neutral firms, actual outputs are stochastic with variance function of planned output, production costs are function of planned outputs, while the market (linear) demand function is stable. If individual outputs as positively correlated expected profit is decreased by the negative covariance between output and price. The firms and market equilibria are analyzed in the short run and the long run (with varying number of firms), they are compared with Ois and Tisdells uncertain demand models.