A dynamic approach to road freight flows modeling in Spain

This paper presents an innovative approach to analyzing road vehicle freight traffic that uses a dynamic panel data specification derived from a gravity model. This dynamic approach, which has recently been employed in international goods trade models in lieu of the traditional static specification, is applied to the case of Spain using data for the countrys 15 NUTS-3 regions between 1999 and 2009. Using the system general method of moments approach, we obtained significant evidence that the flow of vehicles carrying commodities by road has a strong persistence effect when controlling for unobserved heterogeneity. We also found that the quality of road transport infrastructure has a significant impact on vehicle trips. According to our findings, we suggest that this type of specification be employed in distribution models in which fixed effects and lags of the dependent variable are included to account for unobserved heterogeneity and persistence effects, respectively.     

Hydro-elastic analysis and optimization of a composite marine propeller

The present paper addresses the design and optimization of a flexible composite marine propeller. The aim is to tailor the laminate to control the deformed shape of the blade and consequently the developed thrust. The development of a hydro-elastic model is presented, and the laminate lay-up which minimizes the fuel consumption for the cruising and maximum speed conditions is simultaneously determined. Results show a reduction of 1.25% in fuel consumption for the combined case corresponding to a decrease of 4.7% in the cruising speed condition. Finally, the strength of the optimal blade is analyzed using the Tsai-Wu strength index. After local tailoring of the laminate configuration throughout the propeller a maximum value of 0.7 is determined indicating no failure will occur under normal operation conditions. The results suggest that it is possible to design a medium-sized flexible composite marine propeller that will enable a reduction of the fuel consumption while withstanding the imposed loads     

Telemetric system for monitoring and automation of railroad networks

This paper describes a new method of real-time train monitoring based on the ZigBee/IEEE 802.15.4 protocol. The system consists of a mobile device embedded in the moving train which transmits parameter signals that are being measured by a base unit with the help of routers. When applied, the technique monitors and controls vehicles operating on permanent routes, making a real-time evaluation of their performance and location, and allowing an effective planning of trains. It consists of a low cost, low power consumption and safe modular technology capable of monitoring many different variables simultaneously.     

The future of trucking technology in Brazil: results of a technology forecasting model

Abstract

The aim of this article is to identify a set of technological events related to the Brazilian truck fleet that are well placed hierarchically regarding their possibility of occurrence and pertinence for the horizon year of 2021. For this we propose and apply a Technology Forecasting Model for trucks (called TFM/Trucks) based on the Delphi technique, considering 28 technological events associated with six internal forecasting dimensions: safety, efficient use of energy and alternative fuels, materials technology, operational schemes, comfort and environment. The ranking of the technological events, considering hypothetical situations for analysis, indicate significant concern over the safety dimension, with four of the five events (passive safety and active safety) classified among the 10 events with the greatest chance of occurring and pertinence, irrespective of the panelists' degree of specialization. The environmental dimension, with respect to the predominance of electric powered trucks with lower level of atmospheric pollutants, was always in one of the first two positions, regardless of the situation studied. In the final ranking, the five best-classified events represented the dimensions of safety, environment, materials technology and comfort, with environment and passive safety predominating.     

What determines university student’s willingness to pay for bikeways?

Transportation - Inadequate infrastructure is recognized as an important barrier to cycling; therefore, improvements in the provision of bicycle facilities, such as bikeways, are frequently...     

Book Review: Airline Marketing and Management

Abstract

Public transport policy in the Madrid Metropolitan Area is often deemed as a success. In 1985, an important reform was carried out in order to create a new administrative authority to coordinate all public transport modes and establish a single fare for all of them. This reform prompted a huge growth in public transport usage, even though it reduced the funding coverage ratio of the transport system. Since then, Madrid’s public transport system has been undergoing an increasing level of subsidization, which might jeopardize the financial viability of the city public transport system in the future. In this paper, we present a detailed analysis of the evolution of the public transport funding policy in Madrid in recent years. We found that the increasing level of subsidy can hardly be explained on the basis of equity issues. Moreover, we claim that there is still room for a funding policy that makes the efficiency of the system compatible with its financial sustainability.     

Transition between Signal Timing Plans: A Methodological and Analytical Overview

Abstract

The transition phase is generally defined as the process of switching from one timing plan to another; this process may include changes in offset, phase split or cycle length until coordination for a new timing plan is reached once again. As noted in the literature, transition phases between timing plans may lead to severe disruptions of traffic flow, resulting in potentially lasting effects. The aim of this paper is to comprehensively review, classify and analyse the literature regarding transition between different timing plans to highlight existing research gaps and give researchers a starting point to continue contributing with solutions to the transition problem. Regarding transition approaches, a gap concerning mathematical approaches was deemed significant as a transition could be greatly benefited by simultaneously optimising more than one operational measure of effectiveness through multi-objective mathematical models. Moreover, in the analysis of applied approaches, Shortway algorithms generally outperformed other practical methods under different scenarios.     

PantoCat statement of method

The pantograph–catenary dynamic interaction analysis program (PantoCat) addresses the need for a dynamic analysis code able to analyse models of the complete overhead energy collecting systems that include all mechanical details of the pantographs and the complete topology and structural details of the catenary. PantoCat is a code based on the finite element method, for the catenary, and multibody dynamics methods, for the pantograph, integrated via a co-simulation procedure. A contact model based on a penalty formulation is selected to represent the pantograph–catenary interaction. PantoCat enables models of catenaries with multiple sections, including their overlap, the operation of multiple pantographs and the use of any complex loading of the catenary or pantograph mechanical elements including aerodynamic effects. The models of the pantograph and catenary are fully spatial being simulated in tangential or curved tracks, with or without irregularities and perturbations. User-friendly interfaces facilitate the construction of the models while the post-processing facilities provide all quantities of interest of the system response according to the norms and industrial requirements.