The effect of the competition between cars and trucks on the evolution of the motorway transport system

Motorways, which were devised at the beginning of their history as dedicated roads intended to be traveled by cars only, are at present also traveled by considerable flows of trucks. This fact has deeply changed the motorway transport system with respect to its original conception, owing to the interactions between two categories of vehicles whose characteristics are very different. These interactions greatly increase the transport cost perceived by car drivers with respect to truck drivers. This paper studies the consequences of this cost asymmetry on the evolution of the transport system when the geometric characteristics of a motorway remain unchanged in time, while transport demand increases. By using a theoretical model of competition between cars and trucks, it is shown that, if both the geometric characteristics of a motorway and the increase rate of the activities that feed the transport demand remain unchanged over time, the competition between cars and trucks, as well as the fact that in general passengers have better transport alternatives than freight, make the increase rate of truck traffic greater than that of cars, causing a progressive increase in the proportion of trucks in the time periods in which a motorway is traveled by both the vehicle categories. Since truck traffic on motorways, at least in Europe, is very scarce on weekends and in holiday periods, in which motorways are traveled almost only by cars, these results seem to indicate a tendency to the specialization of motorways, which are likely to be used in the future mostly by only one category of vehicles in different periods of time.     

The car pooling problem: Heuristic algorithms based on savings functions

The present research deals with car pooling as a means of making better use of existing infrastructure and as a means of reducing traffic congestion with all its associated induced effects. Car pooling schemes involve several drivers getting together to share a private vehicle simultaneously, in order to reach their destinations points according to a semi‐common route rather than each driver using their own vehicle. The Car Pooling Problem belongs to the non‐polynomial computational complexity family of operations problems. In the current literature there are only a few studies on this optimization problem: the research group has designed several different new automatic and heuristic data processing routines to support efficient matching in car pool schemes. These are based on savings functions and belong to two distinct macro classes of algorithms to give two different modelings of this problem. They offer average savings of more than 50% in traveled distances demonstrating the effectiveness of a trivial matching scheme for real applications.     

Environmental sustainability in seaports: a framework for successful innovation

Environmental sustainability in the port industry is of growing concern for port authorities, policy makers, port users and local communities. Innovation can provide a solution to the main environmental issues, but often meets resistance. While certain types of technological or organisational innovation can be satisfactorily analysed using closed system theories, in the case of seaports and in particular in the area of environmental sustainability, more advanced conceptual frameworks have to be considered. These frameworks need to be able to account for the multiple stakeholder nature of the port industry and of the network and vertical interactions that environmental sustainability calls for. This article investigates successful innovations improving environmental sustainability of seaports. The proposed framework builds in part on research concepts developed in the InnoSuTra EU FP7 project. From a methodological perspective, this article develops a method for quantifying the degree of success of innovation with respect to a set of specific objectives. Several case studies are used to test the framework against real innovation examples, such as onshore power supply, or alternative fuels. In this article, we argue that only those innovations that fit dynamically port actors’ demands and the port institutional environment stand a chance to succeed.     

Optical device for measuring the injectors opening in common rail systems

Since the needle displacement exerts a fundamental influence on the operation of Common Rail injection systems, accurate measurements of the control piston position can be crucial for a more thorough analysis of the behaviour of injectors, in particular when multiple injections are employed. Eddy current sensors have traditionally been used in lab activities to measure the control piston position inside injectors; apart from the high cost, the scientific literature clearly shows their inadequacy, which is mainly due to the presence of electromagnetic disturbance: the current pulse, which controls the opening of the injector, generates electromagnetic fields which strongly affect the acquisition of data. Many attempts have recently been made either to solve the interference occurring during such measurements or to propose alternative displacement transducers whose operation is not influenced by electromagnetic interference. In this paper, a new device for measuring the injector opening is proposed: it is an optical transducer characterized both by simple and very cheap construction and by a reliable physical principle for measuring the control piston lift. The reliability of the proposed sensor is assessed by a thorough experimental campaign and by comparing the experimental results with the numerical predictions achieved by a Common Rail injector model. Since the assembly of the optical sensor does not affect the injector operation, it can efficiently be used both for experimental tests and for on-board diagnosis and monitoring of the injector operation.     

Sustainability perspectives when crop use is implemented in different sectors: A life cycle assessment approach

The present study aims to provide a preliminary overview of the sustainability concept when biomasses conceived for food goals become the raw materials upon which different sectors, such as plastic or energy industry, can develop innovative strategies, according to a so called ??greener?? competitiveness. In the results hereafter presented, the definition of sustainability perspectives, according to the use of a life cycle assessment (LCA) approach, will be described for maize use as raw material in different sectors. The current biopolymer industry and conventional biofuel technologies, the so called first-generation biofuels, are the more and more in competition with the food sector. The presented environmental evaluation, in terms of air emissions, energy and water consumption, is useful in order to understand the sustainability of a bio-sourced product, in comparison with the equivalent item produced by fossil fuels.     

Home-work carpooling for social mixing

Transportation - Shared mobility is widely recognized for its contribution in reducing carbon footprint, traffic congestion, parking needs and transportation-related costs in urban and suburban...     

Network economies in liner shipping: the role of home markets

This paper deals with the measurement of the network complexity of some selected shipping groups, also identifying the contribution of co-operative agreements among carriers. The empirical investigation is focused on: (i) the analysis of the distribution of the carrying capacity per range; and (ii) the comparison of that capacity with the throughput handled in the port facilities of the group. These variables are interpreted in the light of the impact that alliances have on the geographical wideness of the services supplied by each partner. This factor also allows to depict how the cultural and political origin of shipping lines affects the decision of joining an alliance and the outcomes deriving from such co-operation.     

Ports,external costs,and Northern Italian transport network design: effects for the planned transformation

Modern ports need to be inserted in an efficient network in order to exploit all their potential, positively affecting both the efficiency of the local markets and the external costs of the served industries. Moreover, the role of the ports within the whole supply chain is affected by the location and the organization of intermediate facilities—such as logistics parks or inland ports—that heavily influence both the effectiveness of the logistics corridors and the externalities generated by the transport industry. New and adequate infrastructures can then reduce congestions, pollution, and accidents smoothing the whole logistics chains. The proposed study aims at discussing the effects in terms of rail share of the different planned interventions that are aimed at increasing the rail capacity of the network under investigation. In order to achieve this goal, a network optimization model has been solved by the optimizer solver of a spreadsheet. Outcomes can be used in order to improve current transport policies that might foster a more efficient and less impacting hinterland transport solution.     

PID Controller Modelling and Optimization in Cr Systems with Standard and Reduced Accumulators

The proportional-integrative-derivative (PID) controller and the pressure control valve of a Common Rail system are modelled by taking into account electronic, electrical, hydraulic and mechanical aspects. A fully predictive model of the injection apparatus is realized and validated by means of comparison with experimental data. The effects of the PID parameters on the injection system dynamics are illustrated and discussed on the basis of model results, which refer to steadystate and transient working conditions. The influence of the accumulator size on the rail pressure time history is investigated when the rail volume is dramatically reduced (up to 2.5 cm³). In particular, the effect of the large rail pressure drop that occurs at the end of the main injection for Minirail layout solutions is examined when after injections are implemented. An objective is to try to determine possible suitable values of the PID controller parameters and of the pressure-sensor sampling-frequency for rails of reduced size.     

How to turn an innovative concept into a success? An application to seaport-related innovation

The main objective of this paper is ‘to assess the conditions, including policy support, under which innovative concepts have a high chance of getting adopted and being successful’. The work will start from the state-of-the-art with the following goals targeted. Firstly, to identify the paths that new innovative concepts usually follow, what key determinants are, which actors are involved, and what policy has been doing and can do. As part of this, a typology of variables is established, which will be the basis for the identification of successful adoption paths. Illustrations are provided of the performance of different innovative concepts in the seaport sector. A further goal is to propose policy recommendations, identify best practices, barriers to implementation and transferability of innovative concepts and processes. Finally, the research establishes developments needed in assessment methods and a methodological framework if innovative concepts are introduced.