Transportation Networks

In this work both the multimodal hypergraph and the viable hyperpath conceptualizations are presented. The shortest viable hyperpath problem (SVHP) in a multimodal transportation network is defined. We consider a label correcting approach to find the shortest viable hyperpath from an origin to a destination, for different values of the upper limit of modal transfers. Such hyperpaths compose a Pareto-optimal

A freight terminal is a key node in a transportation network and the transit time of containers through this terminal represents one of the most relevant bottlenecks in logistic chains. The system performance reduction and the corresponding increase of transit time are often due to the increase of the freight flow without a corresponding increase of stacking and handling capacity. For this purpose it was decided to approach the problem by a discrete event simulation model, in order to reproduce the activities carried out inside an intermodal terminal, to calculate the total transit time and to identify the bottlenecks. The transit time of a cargo unit in a terminal is the summation of times required for the development of each phase of the process (waiting time + operational time). Therefore, the first step was the identification of the main activities and the analysis of waiting and operational phases, in order to quantify the times of each phase. For modelling the software Planima...

Assessing the importance of transportation facilities is an increasingly growing topic of interest to federal and state transportation agencies. In the wake of recent terrorist attacks and recurring manmade and natural disasters, significant steps are needed to improve security at both state and metropolitan level. This paper proposes a heuristic procedure using concepts of complex networks science to assess the importance of highway transportation networks using travel time as the performance measure to assess criticality. We demonstrate the proposed technique both in a theoretical network (Sioux Falls network) and in a built-up network to assess the criticality of the major infrastructures that are used to access Manhattan in an AM peak hour. The results demonstrate the efficacy of the procedure to determine critical links in a transportation network.

Transportation projects will have impact on the environment. The general environmental pollution and damage caused by roads is closely associated with the level of economic activity. Although Environmental Impact Assessments (EIAs) are dependent on geo-spatial information in order to make an assessment, there are no rules per se how to conduct an environmental assessment. Also, the particular objective of each assessment is dictated case-by-case, based on what information and analyses are required. The conventional way of Environmental Impact Assessment (EIA) study is a time consuming process because it has large number of dependent and independent variables which have to be taken into account, which also have different consequences. With the emergence of satellite remote sensing technology and Geographic Information Systems (GIS), this research presents a new framework for the analysis phase of the Environmental Impact Assessment (EIA) for transportation projects based on the integration between remote sensing technology, geographic information systems, and spatial modeling. By integrating the merits of the map overlay method and the matrix method, the framework analyzes comprehensively the environmental vulnerability around the road and its impact on the environment. This framework is expected to: (1) improve the quality of the decision making process, (2) be applied both to urban and inter-urban projects, regardless of transport mode, and (3) present the data and make the appropriate analysis to support the decision of the decision-makers and allow them to present these data to the public hearings in a simple manner. Case studies, transportation projects in the State of Florida, were analyzed to illustrate the use of the decision support framework and demonstrate its capabilities. This cohesive and integrated system will facilitate rational decisions through cost effective coordination of environmental information and data management that can be tailored to specific projects. The framework would facilitate collecting, organizing, analyzing, archiving, and coordinating the information and data necessary to support technical and policy transportation decisions.

Abstract: Landfill selection in an urban area is a critical issue in the urban planning process because of its enormous impact on the economy, ecology and the environmental health of the region. With the growth of urbanization as well as the desire to live in cities, lager ...

... These landmarks come to symbolize cities, areas within cities, and neighborhoods. ... The final score for evaluating the inherent clarity or legibility of alternative bus networks combined the performance score for each individual measure or indicator. ...

Drawing on practical experiences of almost 15 years working within Gauteng Province and the City of Johannesburg my paper will focus on the location of poor communities within Johannesburg in relation to selected Inner-City areas and public transportation networks. The introduction notes the historical foundations and spatial legacies of the City (for example, the mining industry, pre and post apartheid doctrines and migration patterns). It acknowledges that these foundations, legacies and future characteristics City are shaped by diverse and complex rationalities that are frequently misunderstood or contradictory. As an example, the paper highlights contradictions and challenges resulting from the conventional, post-1994, housing supply rationale with the demands and needs of low income communities. A working definition of the “urban poor” within the City is proposed; the definition premised on Household Income and Unemployment Indicators. The paper considers the means and location...

Social network analysis (SNA) is not a formal theory in soci- ology but rather a strategy for investigating social structures. As it is an idea that can be applied in many fields, we study, in particular, its influence in the information sciences. Information scientists study publication, citation and ...