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111.
The effect of financial constraints on the optimal design of public transport services 总被引:1,自引:0,他引:1
Recent experience with the design of bus services in Santiago, Chile, seems to confirm Jansson's (1980) assertion regarding
observed planned bus frequency and size being too low and too large, respectively. We offer an explanation based upon the
relation between cost coverage, pricing and optimal design variables. We recall that average social cost decreases with patronage,
which generates an optimal monetary fare below the average operators' cost, inducing an optimal subsidy. Then we compare optimal
frequency and bus size—those that minimize total social costs—with those that minimize operators' costs only. We show that
an active constraint on operators' expenses is equivalent to diminish the value of users' time in the optimal design problem.
Inserting this property back in the optimal pricing scheme, we conclude that a self-financial constraint, if active, always
provokes an inferior solution, a smaller frequency and, under some circumstances, larger than optimal buses.
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Sergio R. Jara-DíazEmail: |
112.
Maria Do Rosário Maurício Ribeiro Macário Joana Duarte Costa Joana André Matias Ribeiro 《运输评论》2015,35(2):226-244
AbstractThis paper uses the Fertagus renegotiation results as a reference and explores the features that made it such a widely commended case, aiming to identify the best practice to be followed in other cases. The two main questions that this paper aimed to respond were: Was the success of the renegotiation process in the Fertagus contract due to mode-specific factors? Are those factors (mode specific or not) transferable to other modes under public private partnership (PPP) contracts and if so, to what extent? Regarding the mode specificity and transferability analysis, it can be noticed that much of the features were not mode specific in theory, however for the successful transferability to other transport modes, some changes should be made to the PPP model taking into account modal specificities and national contexts. 相似文献
113.
Hössinger Reinhard Aschauer Florian Jara-Díaz Sergio Jokubauskaite Simona Schmid Basil Peer Stefanie Axhausen Kay W. Gerike Regine 《Transportation》2020,47(3):1439-1475
Transportation - Based on a time-use model with a sound theoretical basis and carefully collected data for Austria, the value of leisure (VoL) for different population segments has been estimated.... 相似文献
114.
Moyano Amparo Stępniak Marcin Moya-Gómez Borja García-Palomares Juan Carlos 《Transportation》2021,48(6):3301-3324
Transportation - This paper aims to evaluate the impacts of the economic context on traffic congestion and its consequential effects on private vehicle accessibility. We conduct a long-term... 相似文献
115.
The paper deals with the observability problem in traffic networks, including route, origin?Cdestination and link flows, based on number plate scanning and link flow observations. A revision of the main observability concepts and methods is done using a small network. Starting with the full observability of the network based only on number plate scanning on some links, the number of scanned links is reduced and replaced by counted link flows, but keeping the full observability of all flows in the network. In this way, the cost can be substantially reduced. To this end, several methods are given and discussed, and two small and one real case of networks are used to illustrate the proposed methodologies. Finally, some conclusions and final recommendations are included. 相似文献
116.
117.
Gabriele Prati Víctor Marín Puchades Marco De Angelis Federico Fraboni Luca Pietrantoni 《运输评论》2018,38(2):184-208
Bicycle–motorised vehicle (BMV) collisions account for the majority of the recorded bicyclists’ fatalities and serious injuries. This systematic review intends to examine the main factors contributing to BMV collisions. We performed a comprehensive literature review on Scopus, TRID, ProQuest, and Web of Science databases. Fifty-nine English-language peer-reviewed articles met the eligibility criteria and were included in the final analysis. The main factors contributing to BMV collisions identified were classified in accordance with a recently published conceptual framework for road safety. The majority of studies have identified factors related to road users’ behaviour (59.3%) and infrastructure characteristics (57.6%). A minority of studies identified variables related to exposure (40.7%) and vehicles (15.3%) as contributor factors to BMV collisions. A small but significant proportion of studies (20.3%) provided evidence that environmental factors may also play a role, although to a lesser extent, in determining BMV collisions. In addition to the three factors comprised in the applied conceptual framework for road safety, we identified environmental conditions as a category of factors contributing to BMV collisions. 相似文献
118.
The State-owned Spanish Port System (SPS) includes 46 ports for general use that are managed by the 28 port authorities distributed along the 8000 km of Spanish coast. SPS has not grown at a rate comparable to that of international maritime transportation. In our paper, we start from the hypothesis of a port system that appears to be oversized, subsidized, with regard to container traffic. Quantifying the maximum operational capacity of the different container terminals along the Spanish coast and their mooring capacities will provide the available dimensions for this type of traffic. In a second step, we will analyse whether SPS are sufficient (according to the perspective of international standards) to meet Spain’s needs, which is related to Spain’s strategic geographic location and its need to move containerized cargo for the domestic market. The paper concludes SPS has an oversized that limits competitiveness, which is indicated by the average transshipment ratio of approximately 50% and an average unweighted idle ratio of port facilities designed for container traffic of over 60% in the eight main ports. 相似文献
119.
C. Fernández D. F. Llorca M. A. Sotelo I. G. Daza A. M. Hellín S. Álvarez 《International Journal of Automotive Technology》2013,14(1):113-122
This paper describes a real-time vision-based blind spot warning system that has been specially designed for motorcycles detection in both daytime and nighttime conditions. Motorcycles are fast moving and small vehicles that frequently remain unseen to other drivers, mainly in the blind-spot area. In fact, although in recent years the number of fatal accidents has decreased overall, motorcycle accidents have increased by 20%. The risks are primarily linked to the inner characteristics of this mode of travel: motorcycles are fast moving vehicles, light, unstable and fragile. These features make the motorcycle detection problem a difficult but challenging task to be solved from the computer vision point of view. In this paper we present a daytime and nighttime vision-based motorcycle and car detection system in the blind spot area using a single camera installed on the side mirror. On the one hand, daytime vehicle detection is carried out using optical flow features and Support Vector Machine-based (SVM) classification. On the other hand, nighttime vehicle detection is based on head lights detection. The proposed system warns the driver about the presence of vehicles in the blind area, including information about the position and the type of vehicle. Extensive experiments have been carried out in 172 minutes of sequences recorded in real traffic scenarios in both daytime and nighttime conditions, in the context of the Valencia MotoGP Grand Prix 2009. 相似文献
120.
JG Gim nez A. Alonso E. G mez 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2005,43(4):233-244
One of the main limitations of algorithms relating forces and creepages at the wheel/rail contact is the use of a friction coefficient independent of the slip. This paper overcomes this limitation through a modification of the FastSim algorithm (based on the Simplified Theory of Kalker). A friction law based on the local value of the slip is established and the required formulation of the local slip elsewhere in the contact area is presented. Some difficulties of the method and the solutions adopted by the authors are also presented. Finally, the achieved improvements are shown through comparison of the results obtained both with the original and the modified FastSim algorithms. 相似文献