Modeling worldwide highway networks

This Letter addresses the problem of modeling the highway systems of different countries by using complex networks formalism. More specifically, we compare two traditional geographical models with a modified geometrical network model where paths, rather than edges, are incorporated at each step between the origin and the destination vertices. Optimal configurations of parameters are obtained for each model and used for the comparison. The highway networks of Australia, Brazil, India, and Romania are considered and shown to be properly modeled by the modified geographical model. (C) 2009 Elsevier B.V. All rights reserved.

Firm relocation and firm profits : Evidence from the Swedish wholesale trade sector

This study analyses the effects of firm relocation on firm profits, using longitudinal data on Swedish limtied liability firms and employing a difference-in-differnce propensity score method in the empirical analysis. Using propensity score matching, the pre-relocalization differneces between relocating and non-relocating firms are balanced. In addition to that, a difference-in-difference estimator is employed in order to control for all time-invariant unobserved heterogeneity among firms. For matching, nearest neighbour matching, using the one-, two- and three nearest neighbours is employed. The balanacing results indicate that matching achieves a good balance, and that similar relocating and non-relocating firms are being compared. The estimated average treatment on the treatment effects indicate thats relocations has a significant effect on the profits of the relocating firms. In other words, firms taht relocate increase their profits significantly, in comparison to what the profits would be had the firms not relocated. This effect is estimated to vary between 3 to 11 percentage points, depending on the lenght of the analysed period after relocation. 

Performance of incentive contracts in highway PPP projects in Brazil

Private-Public Partnerships (P.P.P.) is a new contractual model institutionalized in 2004 that could be used to remedy to the infrastructure deficit in Brazil. In a context of a principal and agent relation, the public partner goal is to give incentives to the private partner in the contract so that their interests are aligned. This qualitative research presents the findings of an empirical study examining the performance of incentive PPP contracts in Brazil in the highway sector. The goal is to explain how the contracting parties can align their interests in an environment of asymmetric information. Literature identified the factors that can influence PPP design and efficient incentive contracts. The study assesses the contribution of these factors in the building of PPP contracts by focusing on the case of the first and only PPP signed in the highway sector in Brazil which is the MG-050. The first step is to describe the condition of the highway network and the level of compliance of the private partner with the contract PPP MG-050. The second step is to explain the performance of the private partner and conclude if the interests of both partners were aligned in contractual aspects. On the basis of these findings and the analysis of the contract, the study formulates suggestions to improve the draft of PPP contracts from the perspective of the incentive theory of contracts.

Manual para la evaluación de proyectos de vías nacionales y regionales mediante el uso del programa HDM: the Highway Design and Maintenance Standard Model

Incluye Bibliografía

Resolución 423(XIX): Integración física de América Latina mediante la interconexión hidrográfica del Orinoco, el Amazonas y el Plata y la carretera boliviariana marginal de la selva = Résolution 423(XIX): Physical integration of Latin America through the hydrographic interconnexion of the Orinoco, Amazonean River Plate and the trans-jungle border highway of the Bolivarian Nations = Resolution 423(XIX): Intégration physique de l'Amérique latine moyennant l'interconnexion hidrographique des bassins de l'Orénoque, l'Amazone et le Plata, et la construction de la route bolivarienne en bordure de la forêt vierge

Publicado separadamete en cada idioma

Highway Concessions: An Evaluation Methodology

The Transport Unit has developed a project evaluation methodology whereby benefits may be broken down by target groups. To date, this approach has been used in three highway concession projects in Argentina, Chile and Colombia. It is also applicable to other projects where it is important to know how benefits are to be distributed as well as what the overall benefits will be. For general inquiries and information on this methodology, please contact ithomson@eclac.cl.

New approaches by highway agencies in dealing with road users

The context in which society develops has changed. The principles of democracy and human rights, in addition to the explosive development of communications, have encouraged citizens' desire for involvement in many areas which formerly had been the preserve of the State. This is also reflected in the attitudes of public utility customers, who are no longer prepared to accept mediocre service from the bodies responsible; on the contrary, they are increasingly putting pressure on those bodies, demanding better service in return for the charges they pay. Road agencies are no exception. They can no longer maintain their traditional isolation from the public and from users in areas such as decision-making or accountability for results achieved. Furthermore, it is no longer enough to provide road networks; these must be managed in such a way as to ensure improved levels of service, acceptable to users who are more and more demanding. This is why conventional styles of highway management have become unsatisfactory and new approaches are developing. There is a gradual increase in openness to the interests and views of users, who are increasingly considered as partners and participants in management. There are numerous examples in various countries, including those of Latin America, of this significant change; it is likely to cause a major transformation in the way in which public highways are managed. The innovations are recent, many of them still at the embryonic stage. A wide variety of concrete measures have been proposed or tried out. It is not yet possible to predict the size or scope of these changes, or which of them will ultimately become normal practice, but the changes have begun. The purpose of this article is to outline the principal changes which are being observed and the new outlook for road users.

Current issues and prospects in the transport sector: urban transport, rail transport and highway maintenance

This edition of the FAL Bulletin tells of recent events and trends in urban transport, railways and highway maintenance in Latin America and the Caribbean.

Tetrahedral mesh optimization combining boundary and inner node relocation and adaptive local refinement

[EN]This work introduces a new technique for tetrahedral mesh optimization. The procedure relocates boundary and inner nodes without changing the mesh topology. In order to maintain the boundary approximation while boundary nodes are moved, a local refinement of tetrahedra with faces on the solid boundary is necessary in some cases. New nodes are projected on the boundary by using a surface parameterization. In this work, the proposed method is applied to tetrahedral meshes of genus-zero solids that are generated by the meccano method. In this case, the solid boundary is automatically decomposed into six surface patches which are parameterized into the six faces of a cube with the Floater parameterization...