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51.
Abstract

Cost–benefit analysis (CBA) plays a major role in the ex ante evaluation of rail projects in many western countries. At first sight carrying out a CBA for rail projects seems straightforward, since cost estimates are almost always available, and the most dominant benefits are generally known, being the travel time saved and the increase in consumer surplus due to induced demand. However, the practice is much more complex: the quality of current estimates for costs and benefits is often poor and several benefits-related aspects are ignored. This article gives an overview of the challenges in improving the quality of CBAs for rail projects.  相似文献   
52.
Abstract

The growing popularity of electric devices and the increasing number of hybrid and electric cars have recently raised concerns about the use of auditory signals by vulnerable road users. This paper consolidates current knowledge about the two trends in relation to cycling safety. Both a literature review and a crash data analysis were carried out. Based on a proposed conceptual model, knowledge gaps are identified that need to be addressed for a better understanding of the relation between limitations on auditory information while cycling. Results suggest that the concerns regarding the use of electronic devices while cycling and the advent of hybrid and electric vehicles are justified. Listening to music and conversing on the phone negatively influence cyclists’ auditory perception, self-reported crash risk and cycling performance. With regard to electric cars, a recurring problem is their quietness at low speeds. Implications of these findings in terms of cycling safety are discussed.  相似文献   
53.
This paper presents a number of reasons that are responsible for the disappointment of authorities in their operators’ efforts to develop public transport (PT) to the advantage of their travellers. The lessons drawn in this paper are based upon the competitive tendering experience of the authors and upon the results of meetings organised with parties involved in competitive tendering and aimed at exchanging lessons. There appears to be three main causes: (1) there is freedom for the operator, but the contract is bad; (2) there is freedom for the operator, there is a good contract, but there is no market; and (3) there is freedom for the operator, but the operator is not able to use it. The paper concludes with a few perspectives for improvement.  相似文献   
54.
Over the last decade, insights from the strategic management discipline have increasingly been applied to ports. A review of literature shows that in the analysis of port authority strategy, mainly outside-in approaches are applied. This paper adds to the emerging understanding of the port authority’s strategy by applying a cognitive perspective. Specifically, the strategic cognition of firms’ executives is one of the explanatory variables behind firms’ strategic decisions. Furthermore, cognitions are influenced by the organisational contexts in which port authority executives have worked. As a result, managerial “mental maps’ may vary across industry contexts and over time. This research investigates the strategic cognition of a global set of port authority executives through a survey-based instrument. The results show that, to a large extent, PAs resemble “regular” for-profit companies, but that they possess some specific beliefs that distinguish them from “regular” companies.  相似文献   
55.
There is a growing awareness that road networks, are becoming more and more vulnerable to unforeseen disturbances like incidents and that measures need to be taken in order to make road networks more robust. In order to do this the following questions need to be addressed: How is robustness defined? Against which disturbances should the network be made robust? Which factors determine the robustness of a road network? What is the relationship between robustness, travel times and travel time reliability? Which indicators can be used to quantify robustness? How can these indicators be computed? This paper addresses these questions by developing a consistent framework for robustness in which a definition, terms related to robustness, indicators and an evaluation method are included. By doing this, policy makers and transportation analyst are offered a framework to discuss issues that are related to road network robustness and vulnerability which goes beyond the disconnected definitions, indicators and evaluation methods used so far in literature. Furthermore, the evaluation method that is presented for evaluating the robustness of the road network against short term variations in supply (like incidents) contributes to the problem of designing robust road networks because it has a relatively short computation time and it takes spillback effects and alternative routes into account.  相似文献   
56.
A particle-tracking individual-based model (IBM) coupled with a 3-D hydrodynamic model was used to investigate how spatial variability in spawning and nursery grounds may influence transport and retention of sardine (Sardinops sagax) eggs and larvae in the southern Benguela ecosystem. A temperature-dependent Bělehrádek development model based on laboratory growth data was used to determine the duration of one egg and two larval stages. Successful transport/retention depended on each particle's stage of development rather than its age. Results show that recruitment could occur in two distinct nursery areas on the west and south coasts of South Africa. Three viable recruitment ‘systems’ were identified: two are retention-based (spawned and retained on the west coast (WC–WC) or the south coast (SC–SC)) and one is transport-based (spawned on the south coast and transported to the west coast (SC–WC)). In the WC–WC system, the vertical distribution of eggs influenced retention; at intermediate depths of spawning (25–50 m) eggs avoided both offshore Ekman drift and deep cold water. In the SC–SC system, the area of spawning was important; > 50% of eggs from the eastern Agulhas Bank (EAB) were retained in the south coast nursery grounds, whereas very few eggs were transported there from west of Cape Agulhas. In the SC–WC system, area of spawning was also important; 40% of the eggs spawned on the western Agulhas Bank (WAB) were transported to the west coast nursery ground. Sardine life history strategy could be divided between two main systems: the west coast system (spawning on the WAB and WC, and recruiting to the WC) and the Agulhas Bank system (spawning on the central and eastern Agulhas Bank, and recruiting to the SC).  相似文献   
57.
Airport noise nuisance is a negative externality especially when it occurring near urban areas. Like all externalities, noise nuisance may be a reason for government intervention. When intervening, governments should set quantitative policy targets with care. In practice, this issue is generally neglected. This line of research sets the first step towards determining optimal policy targets in the case of noise nuisance near airports, more specifically in the case of Amsterdam Airport. We use hedonic pricing to establish the benefits of noise reduction. Furthermore, we develop a bottom-up cost function to analyze the costs of reducing noise for airlines. We then equate marginal costs and benefits to establish the optimal level of noise reduction, which appears to be 3 dB in the case of Amsterdam Airport. Welfare increasing measures include alternative approach procedures, regional substitution of planes within existing fleets and early depreciation of noisy planes increase welfare. Reducing the number of flights has a negative effect on net welfare.  相似文献   
58.
This article presents the results of a study exploring travellers’ preferences for middle-distance travel using Q-methodology. Respondents rank-ordered 42 opinion statements regarding travel choice and motivations for travel in general and for car and public transport as alternative travel modes. By-person factor analysis revealed four distinct preference segments for middle-distance travel: (1) choice travellers with a preference for public transport, (2) deliberate-choice travellers, (3) choice travellers with car as dominant alternative, and (4) car-dependent travellers. These preference segments differ in terms of the levels of involvement and cognitive effort in travel decision making, the travel consideration-set and underlying motivations. The study showed that for most people there is more to travel than getting from point A to point B, and that there is considerable heterogeneity in middle-distance travel preferences. Policy implications for reducing the need for travel and promoting a modal shift from car to other travel modes are discussed.  相似文献   
59.
60.
Abstract

This paper seeks to identify enablers and barriers that stimulate or prevent the adoption of alternatively powered buses (APBs) in cities. The research method concentrates on an in‐depth analysis of 21 European demonstration case studies of APBs. Considerable differences exist between these cities due to the different reference situation. The type of measurement and the situation in the demonstration cities influence the exact fuel consumption and emission reduction. Variables that could enable the adoption of all types of APBs are: (1) the compatibility with previously introduced ideas; (2) the already available necessary supporting infrastructure in the city; (3) a changed external appearance of the APB; (4) the acceptance of the APBs by passengers and bus drivers; and (5) political support in the city regarding the APBs. The main variables that could be determined as barriers are: the relative economic advantage (the outline of costs is higher than that of conventional buses); and the understanding of the APB for bus drivers and mechanics (because special training is needed for both groups).  相似文献   
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