9,063 research outputs found
Computational Challenges in Cooperative Intelligent Urban Transport
This report documents the talks and group work of Dagstuhl Seminar 16091
“Computational Challenges in Cooperative Intelligent Urban Transport”. This
interdisciplinary seminar brought researchers together from many fields
including computer science, transportation, operations research, mathematics,
machine learning and artificial intelligence. The seminar included two formats
of talks: several minute research statements and longer overview talks. The
talks given are documented here with abstracts. Furthermore, this seminar
consisted of significant amounts of group work that is also documented with
short abstracts detailing group discussions and planned outcomes
Influences on aircraft target off-block time prediction accuracy
With Airport Collaborative Decision Making (A-CDM) as a generic concept of
working together of all airport partners, the main aim of this research project was to
increase the understanding of the Influences on the Target Off-Block Time (TOBT)
Prediction Accuracy during A-CDM. Predicting the TOBT accurately is important,
because all airport partners use it as a reference time for the departure of the flights after
the aircraft turn-round. Understanding such influencing factors is therefore not only
required for finding measures to counteract inaccurate TOBT predictions, but also for
establishing a more efficient A-CDM turn-round process.
The research method chosen comprises a number of steps. Firstly, within the
framework of a Cognitive Work Analysis, the sub-processes as well as the information
requirements during turn-round were analysed. Secondly, a survey approach aimed at
finding and describing situations during turn-round that are critical for TOBT adherence
was pursued. The problems identified here were then investigated in field observations
at different airlines’ operation control rooms. Based on the findings from these previous
steps, small-scale human-in-the-loop experiments were designed aimed at testing
hypotheses about data/information availability that influence TOBT predictability. A
turn-round monitoring tool was developed for the experiments.
As a result of this project, the critical chain of turn-round events and the decisions
necessary during all stages of the turn-round were identified. It was concluded that
information required but not shared among participants can result in TOBT inaccuracy
swings. In addition, TOBT predictability was shown to depend on the location of the
TOBT turn-round controller who assigns the TOBT: More reliable TOBT predictions
were observed when the turn-round controller was physically present at the aircraft.
During the experiments, TOBT prediction could be improved by eight minutes, if
available information was cooperatively shared ten minutes prior turn-round start
between air crews and turn-round controller; TOBT prediction could be improved by 15
minutes, if additional information was provided by ramp agents five minutes after turnround
start
Promoting Intermodal Connectivity at California’s High Speed Rail Stations
High-speed rail (HSR) has emerged as one of the most revolutionary and transformative transportation technologies, having a profound impact on urban-regional accessibility and inter-city travel across Europe, Japan, and more recently China and other Asian countries. One of HSR’s biggest advantages over air travel is that it offers passengers a one-seat ride into the center of major cities, eliminating time-consuming airport transfers and wait times, and providing ample opportunities for intermodal transfers at these locales. Thus, HSR passengers are typically able to arrive at stations that are only a short walk away from central business districts and major tourist attractions, without experiencing any of the stress that car drivers often experience in negotiating such highly congested environments. Such an approach requires a high level of coordination and planning of the infrastructural and spatial aspects of the HSR service, and a high degree of intermodal connectivity. But what key elements can help the US high-speed rail system blend successfully with other existing rail and transit services? That question is critically important now that high-speed rail is under construction in California. The study seeks to understand the requirements for high levels of connectivity and spatial and operational integration of HSR stations and offer recommendations for seamless, and convenient integrated service in California intercity rail/HSR stations. The study draws data from a review of the literature on the connectivity, intermodality, and spatial and operational integration of transit systems; a survey of 26 high-speed rail experts from six different European countries; and an in-depth look of the German and Spanish HSR systems and some of their stations, which are deemed as exemplary models of station connectivity. The study offers recommendations on how to enhance both the spatial and the operational connectivity of high-speed rail systems giving emphasis on four spatial zones: the station, the station neighborhood, the municipality at large, and the region
Technology: a necessary but not sufficient condition for future personal mobility
NĂşmero especial: Sustainable Road Transportation Planning[Abstract:] Technological advances revolutionize industrial processes, science, communications, and our way of life. However, developed societies have reached a stage in which the fascination with technological innovations often results in their indiscriminate consumption. In this paper, road traffic is used as a line of argument to demonstrate that the random introduction of technology does not imply benefits to society. Particularly, it is analyzed why some of the potential benefits of technological progress are lost in fields such as traffic monitoring, data handling, and traffic management, or in sustainable mobility initiatives, such as the introduction of electric vehicles or the implementation vehicle sharing projects. The risks faced in the future advent of autonomous vehicles are also discussed, and ideas for improvement suggested. A critical reflection on other transportation modes that are expected to be realized in the near future is included as well. The performed analysis evidences that the potential improvement in personal mobility will not become a reality if it exclusively relies on the latest technological devices, in line with consumers’ fantasies or economic interests. This is a statement that could be generalized to many other fields. The implementation/consumption of a particular technology should not be an objective in itself, but a tool to bring benefits to society.Ministerio de EconomĂa y Competitividad; TRA2016-79019-R/COO
Generic model for resource allocation in transportation: Application to urban parking management
In this paper, we define the online localized resource allocation problem, especially relevant for modeling transportation applications. The problem modeling takes into account simultaneously the geographical location of consumers and resources together with their online nondeterministic appearance. We use urban parking management as an illustration of this problem. In fact, urban parking management is an online localized resource allocation problem, where the question is how to find an efficient allocation of parking spots to drivers, while they all have dynamic geographical positions and appear nondeterministically. We define this problem and propose a multiagent system to solve it. The objective of the system is to decrease, for private vehicles drivers, the parking spots search time. The drivers are organized in communities and share information about spots availability. We have defined two cooperative models and compared them: a fully cooperative model, where agents share all the available information, and a 'coopetitive' model, where drivers do not share information about the spot that they have chosen. Results show the superiority of the first model
Fiscal federalism : dimensions of tax reform in developing countries
The authors propose four economic principles for use in deciding taxing responsibilities for various levels of government. These are: 1) efficiency of the internal common market - for efficiency in internal common market, taxes on mobile factors and tradable goods should either be assigned to the national government or coordinated among subnational governments; 2) national equity - progressive redistributive taxes ought to be assigned to the level of government having responsibility for redistribution, usually the national government. Subnational governments could levy supplementary flat rates on the federal tax base; 3) administrative costs - to minimize collection, administration, and compliance costs, a tax should be assigned to the level likely to be best informed about its base. This suggests assigning real property taxation to local governments and corporate income taxation to the national government; and 4) fiscal need - to ensure accountability, revenue means should be matched as closely as possible to revenue needs. Thus tax instruments intended to further specific policy objectives should be assigned to the level of government having the responsibility for such a service. Thus progressive redistributive taxes, stabilization instruments, and resource rent taxes would be suitable for assignment to national government; while tolls on intermunicipal roads are suitably assigned to state governments. Some resource taxes, such as royalties and fees and severance taxes on production and/or output, are designed to cover costs of local service provision and could be assigned to subnational governments. In addition, subnational governments could also impose taxes to discourage local environmental degradation. In countries with a federal level VAT, it may be too cumbersome to have subnational sales taxes. In such circumstances, the fiscal need criterion would suggest allowing subnational governments access to taxes which are traditionally regarded as suitable for national administration, such as personal income taxes. The authors also stress the importance of tax harmonization and coordination in preserving internal common market, reducing collection and compliance costs and helping to achieve national equity objectives and suggest methods of achieving such coordination vertically (between the federal and subnational governments) and horizontally (among subnational governments).Municipal Financial Management,Public Sector Economics&Finance,National Governance,Banks&Banking Reform,Environmental Economics&Policies
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