The main objective of this article is to gain fundamental understanding on the effect of real time information acquisition, on the traffic conditions of the Athens greater area. Activity scheduling... Show More

The main objective of this article is to gain fundamental understanding on the effect of real time information acquisition, on the traffic conditions of the Athens greater area. Activity scheduling is a dynamic process, where individuals often need to modify their schedule, as a result of new insights. Research so far hasn't analyzed the effect of traffic information acquisition, in activity scheduling, although several studies have been conducted to capture the factors that influence the rescheduling of activities. An integrated latent variable model has been estimated, that predicts the probability of rescheduling activities as a function of flexibility, mode choice constraints and travel information. The analysis of the results indicates that one of the biggest impacts of traffic information acquisition is reflected in the rescheduling of activities. Therefore, traffic information not only can significantly improve the travel experience of individuals but may directly affect the performance of the transportation system.

Promotion of cycling can improve the sustainability level of a city or an urban area. This study presents a methodology that audits the bikeability level of the urban road environment across three... Show More

Promotion of cycling can improve the sustainability level of a city or an urban area. This study presents a methodology that audits the bikeability level of the urban road environment across three selected routes in the city of Volos, Greece. This methodology is a useful toolkit in order to evaluate and improve the bikeability level of the urban road environment and also evaluate existing bikeways. Four suitably trained auditors rode their bikes and evaluated the bikeability level using an audit tool in order to audit specific features that influence bicycling suitability across the road segments and intersections of the selected routes. Furthermore, the auditors graded specific features of the road environment in order to set a bikeability score for each tested route. Finally, this study concludes that the bikeability level of the selected routes was moderate and certain actions are necessary in order to be improved.

The objective of this research is the analysis of pedestrians behaviour along entire trips in urban road networks, with focus on their interaction with the traffic and the road environment while... Show More

The objective of this research is the analysis of pedestrians behaviour along entire trips in urban road networks, with focus on their interaction with the traffic and the road environment while crossing roads. For this purpose, a special field survey was designed and carried out, which involved the recording of pedestrians road crossing behaviour along entire trips in real time by means of camera in motion at the centre of Athens, Greece. Based on the results of the field survey, an analysis of road crossing behaviour of pedestrians is presented, concerning characteristics of the trips, the pedestrians, the road environment and the traffic conditions. The results indicate that basic parameters of pedestrian trips (i.e. trip length, walking speed, number of crossings) can be described by appropriate probability distributions. They also reveal a tendency of pedestrians to cross either in the beginning or in the end of the trip, an increased probability of crossing at signalized junctions when these are available, and increased probability of crossing at mid-block in low traffic volume and on one-way roads. Furthermore, there is an overall tendency of pedestrians cross to at mid-block when the road and traffic conditions are favourable. On the contrary, more traffic lanes and increased traffic volume appear to discourage pedestrians from accepting important interaction with the vehicles and to lead them towards the choice of protected crossing locations. The proposed data collection method and the results of the analysis can be exploited in further research for the development of models of pedestrian crossing behaviour along entire trips in urban areas.

In the current social, physical, economical and environmental circumstances of scarcity, the design and management of vital lifelines like transportation systems, especially within the metropolitan... Show More

In the current social, physical, economical and environmental circumstances of scarcity, the design and management of vital lifelines like transportation systems, especially within the metropolitan context, are subject to the implementation of multiple objectives in a unified framework. Thus, one of the most important issues is the identification of optimal trade-offs among crucial objectives both from the designer's as well as from the users' perspective. In the current study a comprehensive framework for estimating optimal interrelations and dilemmas among emissions-related carbon footprint and other (social- and economic-related) features of urban road networks design and operation are presented and analyzed, based on techniques of multi-objective and hierarchical mathematical programming with equilibrium constraints, solved by suitable hybridization of evolutionary algorithms. The results of the proposed optimization methodological approach provide the Pareto Frontier of solutions, which corresponds to optimal trade-offs amongst multiple objectives. The computational experience from the application of the proposed methodological approach on a part of a realistic urban network is presented, providing evidence on the applicability as well as on the computational burden of such transportation design paradigms, but most importantly, on the dilemmas emerging in sustainable design and planning of transportation systems.

Recent natural disasters highlight the complexities associated with planning, coordination and distribution of supplies in a manner which provides timely and effective response. In this paper, the... Show More

Recent natural disasters highlight the complexities associated with planning, coordination and distribution of supplies in a manner which provides timely and effective response. In this paper, the authors present a model to quantify the benefits associated with pre-positioning local supplies. They assume the supplies are in a high-risk location and may be destroyed if an appropriate strategy to protect the supplies is not implemented. A stochastic linear programming model is developed where the first-stage decision pre-positions existing supplies to minimize the supply loss. Second-stage decisions attempt to maximize the responsiveness of the system by allocating supplies to satisfy demand. The benefits associated with pre-positioning versus non-pre-positioning are discussed.