Michael A. Madas

Optimizing intermodal trip planning decisions in interurban networks

Travel and tourism activities and trip planning decisions involving the interoperability complexities and interdependencies introduced by inter-modal and interurban transportation networks constitute an ample opportunity area for deploying the state-of-the-art mobile Internet technologies. It is becoming increasingly necessary to provide travelers with real-time information to assist them in preplanning or replanning their transport and travel activities or particular trip elements during their trip, while being on the move. Trip planning decisions, either before or during the trip realization constitute a derived demand, pushed by demand for tourism activities. However, they represent the most critical chain of the decision-making process on the grounds that they eventually determine the feasibility and the realization of the whole travel activity. From a different perspective, terminal operators, regional authorities, and other transport and tourism organizations show a vast interest and actively pursue alternative ways of dealing with the requirements of the demand for travel and tourism services. An integrated system providing value added logistical services related to travel and tourism, the World in your H@nds on the Move–WH@M system, has been implemented to support and optimize the trip planning process. A study had three objectives: to discuss the way that intermodality can be supported by such a technological application; to present the architecture, operations, and the solution approach governing the trip planning modules; and to provide a brief demonstration of the relevant trip planning modules of the system.

Increasing airport capacity utilisation through optimum slot scheduling: review of current developments and identification of future needs

Most of the busiest airports worldwide experience serious congestion and delay problems which call for some immediate capacity and demand management action. Solutions aiming to manage congestion through better slot scheduling have lately received a great deal of consideration due to their potential for delivering quick and substantial capacity utilisation improvements. A slot scheduling approach brings promises to cope better with congestion problems in the short to medium run and in a more sustainable way based on existing resources. This paper aims to provide a critical review of current research in declared capacity modelling and strategic slot scheduling. Furthermore, it goes beyond the critical review of current research developments by identifying future research issues and gaps and developing concrete directions towards modelling and solving advanced single airport and network-based slot scheduling problems. Our research findings suggest that the next generation of slot scheduling models should explore variations of currently used objectives (e.g., alternative expressions of schedule delay) and most importantly enrich them with fairness and equity, resource utilisation and environmental considerations. Future modelling efforts should also aim to further investigate airlines’ utility of alternative slot allocation outcomes, including various acceptability measures and levels of tolerance against schedule displacements. Last but not least, future research should intensively focus on the development and validation of computationally viable and robust slot scheduling models being able to capture the complexity, dynamic nature and weather-induced uncertainty of airport operations, along with hybrid solution approaches being able to deal with the size and complexity of slot allocation at network level.

Advanced Modeling Capabilities for Airport Performance Assessment and Capacity Management

Airport decision makers face frequently complex decisions related to airport planning, design, and operations. These decisions are highly complicated since they involve a variety of entities processed through the system, a number of different airport elements, and a large variety of airport performance measures such as capacity, delays, safety, security, noise, and cost-effectiveness. Existing airport modeling capabilities suffer from (a) fragmentation between the various airport elements, entities, and their operations; (b) the isolated manner in which the airport performance measures are assessed and modeled; and (c) the lack of user-friendly modeling capabilities and decision support systems adopting a problem-oriented approach for airport decision making and planning. Advanced airport modeling capabilities should be deployed to integrate domain knowledge with tool expertise in assisting airport decision makers to answer frequently arising airport planning questions in an integrated, user-friendly, and problem-oriented environment. The operational concept for an integrated, problem-oriented modeling approach for total airport performance analysis is introduced, the development of a decision support system for airport performance assessment and capacity management is described, and the modeling and decision support capabilities of the system are demonstrated.

CRITICAL ASSESSMENT OF AIRPORT DEMAND MANAGEMENT STRATEGIES IN EUROPE AND THE UNITED STATES: COMPARATIVE PERSPECTIVE

The ever-tighter mismatch between the demand and supply of airport services has triggered policy discussions that bring to the forefront a challenging dilemma for decision makers and the various stakeholding groups in the airport domain: demand management or capacity enhancement? There are two solutions in the effort to reduce gridlock in the air transport system—to expand capacity, and to diminish or handle demand through time and space. One part of the answer lies with technology and operations aiming at building capacity and another with balancing and handling demand. Since the last decade of continuously increasing air traffic congestion, demand management strategies have gained increasing acceptance by airport authorities and policy makers as a potential vehicle of handling demand—by limiting in some way the demand for access to busy airfields or to congested airspace or by modifying the spatial and temporal distribution of demand, or by doing both. A critical review was done of the developments, practices, and research activities in Europe and the United States toward confronting the well-known aviation capacity gridlock. A triplet of analysis formed the base: the current state of affairs pertaining to the demand and growth patterns and prospects vis-à-vis supply-side developments; the discussion of the aviation capacity gridlock; and an in-depth analysis and critical assessment of the alternative demand-side solutions under the spectrum of all potential enhancement aspects (i.e., administrative, economic, hybrid measures).