CONGRESS |
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90th Transportation Research Board Annual Meeting - TRB
Place and date: Washington, 23 - 27 January 2011
Presentation:
Annual congress of the Transportation Research Board (TRB), one of them institucions U.S. National Research Council dedicated to research on issues of Transport.
Papers:
- "The value of time influence in the profitability of railway projects: theorethical formulation and case study". Criado, O., M. Sánchez-Borràs and F. Robusté.
- "High-speed railways in Spain: An example of success?". Sánchez-Borràs, M., F. Robusté. and O. Criado.
- "Evaluation of speed limit management C-32 highway access to Barcelona". Soriguera, F., D. Rosas and J.M. Torné.
- "ICT based estimation of time dependent origin-destination matrices". Barcelo, J., L. Montero, L. Marques and C. Carmona.
- "Assessment of the public transportation supply in a local level". Campos, J.M, G. Alsina and M. Estrada.
- "Tandem Bus Stop Capacity". Estrada, M., J. Ortigosa and F. Robusté.
- "Car Carriers Operations: An Empirical Approach". Saurí, S., E. Martín and B. Spuch.
- "Evaluating pricing strategies for storage in import container terminals". Saurí, S., E. Martín and J. Serra.
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PAPERS |
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The value of time influence in the profitability of railway projects: theorethical formulation and case study.
Authors: Criado, O., M. Sánchez-Borràs and F. Robusté.
Congress: 90th Transportation Research Board Annual Meeting - TRB.
Place and date: Washington, 23 - 27 January 2011.
Language: english
Summary:
The recent worldwide crisis scenario has imposed limitations on public and private spending on new transport infrastructures. As a result, there is a need for new stricter criteria in order to prioritize some projects over others in a more socio-economically efficient way. The Project Appraisal is a common tool used for this matter.
The Value of Time (VOT) is a relevant element in transport project appraisal. On the one hand, it is essential for the calculation of the gain derived from the reduction of time for users obtained by the development of a project. On the other hand, the ex-ante prediction of demand of the planned infrastructure is made on the basis of the VOT and, consequently, its estimation is a key element for the determination of the global modal split.
This paper analyzes the VOT influence on the profitability of railway projects. Specifically, the components affected by the VOT are studied on the basis of a railway project appraisal manual. The analysis is performed from two different points of view. First, a theoretical formulation is deduced for the relation between the VOT, included in the cash flow of the different components identified, and the Internal Rate of Return (IRR), representative of the profitability of an infrastructure project. Second, a practical case for a suburban railway line is studied in order to identify the sensitivity of the IRR to the VOT, that is to say, the influence of the VOT on the profitability of the project.
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High-speed railways in Spain: An example of success?.
Authors:Sánchez-Borràs, M., F. Robusté. and O. Criado.
Congress: 90th Transportation Research Board Annual Meeting - TRB.
Place and date: Washington, 23 - 27 January 2011.
Language: english
Summary:
The Spanish high-speed railway (HSR) network has developed very swiftly over the past few years. In less than two decades, this network has already become the second longest in Europe and the third in the world ranking, and it continues to grow.
Given this situation, and given that the Spanish HSR system is considered by several governments an example to follow, it is of great interest to analyze whether the Spanish case can really be considered an example of success in terms of HSR and whether some Spanish practices may be improved upon.
The present paper thoroughly analyzes the Spanish HSR network in terms of its use, competitiveness with air travel, environmental and territorial impacts, and profitability and costs. The results of this analysis allow us to draw a conclusion regarding its success and to make some recommendations to bear in mind when planning the construction of a high-speed line.
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Evaluation of speed limit management on C-32 highway access to Barcelona.
Authors:Soriguera, F., D. Rosas y J.M. Torné.
Congress: 90th Transportation Research Board Annual Meeting - TRB
Place and date: Washington, 23 - 27 January 2011.
Language: english
Summary:
In July 2007, the Autonomous Government of Catalonia passed a 73-measure plan to improve the air quality in the metropolitan region of Barcelona, Spain. This plan (which turned into law in January 2008) included 80 km/h speed limitations on major highways around the city (e.g., the C-32 highway). One year later, dynamic speed limits (DSL), maintaining the maximum speed limit of 80 km/h, became operational. The objective of the present paper is the evaluation of this policy, what requires a quantitative analysis in terms of congestion reduction, vehicles’ emissions and traffic safety.
As the comparison between different scenarios must be performed with homogeneous traffic demands (i.e., same productivity), comparisons from direct empirical measurements are not representative. Note that during the period of analysis, the huge economic recession arrived to Spain resulting in a clear reduction of mobility demands. CTMSIM macroscopic traffic simulator [1, 2] was applied instead, simulating different scenarios under the same demand. Data in order to construct the baseline demand scenario were collected from double loop detectors installed in each lane along 14.5km of the C32 highway, accessing Barcelona.
A quantitative evaluation of the social profitability of this policy in terms of travel times, emissions and safety benefits is provided in the paper. In addition, some guidelines for the construction of homogenous demand scenarios suitable for comparisons, the characterization of fundamental diagrams, the macroscopic model of the highway based on the cell transmission model (CTM) [3, 4], and the definition and assessment of the different elements constituting the objective function in monetary units, are also described.
It is concluded from the discussion, that the speed limit management on metropolitan highways accessing to large cities, cannot provide in case of isolated application significant benefits.
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ICT Based estimation of time-dependent origin-destination matrices.
Authors:Barceló, J., L. Montero, L. Marques y C. Carmona.
Congress: 90th Transportation Research Board Annual Meeting - TRB
Place and date: Washington, 23 - 27 January 2011.
Language: english
Summary:
Time-Dependent Origin-Destination (OD) matrices are a key input to Dynamic Traffic Models, microscopic and mesoscopic traffic simulators are relevant examples of such models, traditionally used to assist in the design and evaluation of Traffic Management and Information Systems (ATMS/ATIS). Dynamic traffic models are also starting to be used to support real-time traffic management decisions. The typical approaches to the time-dependent OD estimation have been based either on ad hoc heuristics using mathematical programming approaches, or on Kalman-Filtering. The advent of the new Information and Communication Technologies (ICT), as for example Automatic Vehicle Location, License Plate Recognition, detection of mobile devices, Vehicle to Infrastructure (V2I) and so on, makes available new types of traffic data of higher quality and accuracy allowing for new modeling hypothesis leading to more computationally efficient algorithms. This paper extends the previous research on Kalman Filtering approaches for Freeway OD estimation using these data, to more complex topologies of urban networks were alternative path choices between origins and destinations are available. Ad hoc procedures based on Kalman Filtering have been designed and implemented successfully and the numerical results of the computational experiments are presented and discussed.
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Assessment of the public transportation supply in a local level.
Authors:Campos, J.M, G. Alsina y M. Estrada.
Congress: 90th Transportation Research Board Annual Meeting - TRB
Place and date: Washington, 23 - 27 January 2011.
Language: english
Summary:
This article presents new methodology for assessing the quality provided by urban surface transit systems in terms of comfort, speed and coverage. A set of robust indicators are presented to measure how transit supply servers the multimodal chain of users (access, waiting and in-vehicle time) as well as the performance of the transit system. These measures are summarized in a unique indicator that accounts for the quality of the global service. The latter may be a useful tool to redefine existing transit systems (routes, frequencies or capacity allocation) to any changes in the spatial or time distribution of demand. This methodology has been implemented to the local bus network in Barcelona (Spain) in order to identify the necessary readjustments between transit supply and demand.
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Tandem Bus Stop Capacity.
Authors:Estrada, M., J. Ortigosa y F. Robusté.
Congress: 90th Transportation Research Board Annual Meeting - TRB
Place and date: Washington, 23 - 27 January 2011.
Language: english
Summary:
Bus stops represent a key bottleneck that produces significant delays in travel times. In major cities, the width of streets is constrained by sidewalks and buildings. In this context, adding on-street loading areas in series is a valid method to increase bus stop capacity. A tandem bus stop is a linear bus stop with two loading areas on a dedicated bus lane where buses serve depending on the sequence in which they arrive at the stop since overtaking is not allowed. The objective of this paper is to provide an analytical methodology to help city planners to choose between conventional and tandem bus stops. This study focuses on the capacity gain of a tandem bus stop in the case where there are buses waiting in line. Current studies are based on simulation results only for particular cases. The model is applied to Barcelona, Spain, where the dwell time is described by a log-normal distribution according to the available empirical data. The results obtained in this paper indicate that a capacity gain of 30 to 70% can be achieved, which allows for substantial commercial speed increasing. If buses spend more time at the service position and the variability is low, the gain is greater. Our results suggest including in the Transit Capacity and Quality of Service Manual a more detailed description of the behavior of urban tandem bus stops, where the “effective number of berths” concept should be considered a variable (instead of constant) that depends on the dwell time characteristics.
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Car Carriers Operations: An Empirical Approach.
Authors:Saurí, S., E. Martín y B. Spuch.
Congress: 90th Transportation Research Board Annual Meeting - TRB
Place and date: Washington, 23 - 27 January 2011.
Language: english
Summary:
Vehicle transportation has become on the most important maritime traffic. Most of the contributions to this traffic have been focused on the operations at the yard, despite operations inside the vessels have an important effect on the rest of the terminal operations. The aim of this paper is to provide an empirical analysis of unloading operations for car carrier vessels. Particularly, the principal problems arising during the operations have been identified by interviewing the staff involved in the operations inside the vessel. Also, the time spent handling vehicles inside holds for several vessels has been studied to find out which probability distribution does the timing of operations follow. Results can provide a guideline to solve the problems of operational processes inside the vessel and measurement of reliability of such operations inside the holds by knowing the probability distribution associated with the time of these operations.
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Evaluating pricing strategies for storage in import container terminals.
Authors:Saurí, S., E. Martín y J. Serra.
Congress: 90th Transportation Research Board Annual Meeting - TRB
Place and date: Washington, 23 - 27 January 2011.
Language: english
Summary:
In most container terminals around the world storage space is scarce and pricing policies are needed in order to increase performance. Specifically, congestion when temporarily storing inbound containers in terminal yards leads to high operational costs. This paper focuses on the introduction of a yeard storae tariff to encourage early pick-up of containers. Differently from previous approaches, the price schedule introduced has a non-zero flat rate. Both demand reactions and changes in pick-up decisions are considered in the analysis. A model is developed for the objective function (profit of the terminal operator). A numerical example illustrates an optimal price schedule and shows how sensitive the profit is to the basic constituents of the model, providing general pricing rules.
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