76 research outputs found
Highway-capacity utilization and investment in transportation corridors
An example of highway-capacity utilization is considered in this paper. It has been observed that severe traffic conditions can exist on one freeway, while traffic on a parallel freeway may be moving almost at the speed limit. It is important to examine the possible causes of this phenomenon to avoid wasteful investments. The major objectives of this paper are, first, to examine the theoretical conditions under which the phenomenon can occur; second, to verify those conditions empirically; and, third, to suggest policies that will reduce the volume of traffic on the congested freeway by increasing the utilization of the other freeway. It is concluded that access and egress costs arising from travel on roads connecting the two main freeways have an important effect on the utilization of the freeways.
Analytical problems in linking an activity model with a transportation network model
Various approaches are considered for linking an activity model with a transportation network model. To explore the underlying analytical properties of the linking mechanisms, a prototype model is considered that has a simplified iterative generation - allocation model of the Garin - Lowry type for the activity component, and a trip assignment model for the transportation component. It is seen that there is an inconsistency with regard to activity behaviour under varying travel conditions, that there is no unique steady-state solution, and that the structural parameters are endogenous rather than exogenous to the model.
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Modeling Land Use and Transportation: An Interpretive Review for Growth Areas
Urban growth is taking new forms in recently urbanized or formerly suburban areas, characterized by low density, heavy dependence on automobile transportation, and multiple activity centers. In order to understand better such ’contemporary urban areas’, researchers need land-use models that realistically capture the key features of such areas and that Can handle detailed data sets.We review the literature on large-scale land-use modeling with this objective in mind. Characterizing the known models along several dimensions describing purpose, Conceptual basis, mathematical content, and level of detail, we select models that are representative of the range of approaches taken. Six of these are reviewed in detail, and four others are discussed more briefly.We find that the existing literature forces one to choose between tractability and suitability for contemporary urban areas, The key omission in the tractable models is economies of agglomeration that would help explain the emergence of subcenters. Most tractable models also lack a dynamic structure suitable for handling rapid disequilibrium growth." Models that contain these two features are suitable for broad-brush computer simulation: but they cannot be calibrated with real disaggregated land-use data. This conclusion leads to some brief suggestions on directions for future work
EVALUATION, PRIORITIZATION AND SELECTION OF TRANSPORTATION INVESTMENT PROJECTS IN NEW YORK CITY.
This article reports on a methodological framework undertaken by the authors to help the stakeholders in The Partnership of the City of NY to understand a group of significant transportation capital investment projects and to provide a means to discriminate among them. The authors\u27 major objects was to inform these stakeholders how to make rational and systematic choices based on economic and transportation grounds, in an environment where appropriate data is lacking, no comprehensive regional transportation plan or objectives are defined, and the decision-making environment is highly fragmented. After the authors define the problem, they discuss details of the analysis, including the methodology used, the data sources, and the cost-benefit models. The authors then introduce the Goals Achievement Matrix for the selection and prioritization of projects. The final selections discuss key results and consider specific and general policy implications. Out of the sizeable number of large-scale transportation investment projects that have been proposed for New York City, eight were selected for close scrutiny and assessment. The authors briefly discuss the top three: the Fulton Transit Center and permanent PATH station, the Penn Station/Farley Post Office, and the Number 7 Subway Extension. These projects scored highest on both transportation benefits and economic development benefits scales
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Modeling Land Use and Transportation: An Interpretive Review for Growth Areas
Urban growth is taking new forms in recently urbanized or formerly suburban areas, characterized by low density, heavy dependence on automobile transportation, and multiple activity centers. In order to understand better such ’contemporary urban areas’, researchers need land-use models that realistically capture the key features of such areas and that Can handle detailed data sets.We review the literature on large-scale land-use modeling with this objective in mind. Characterizing the known models along several dimensions describing purpose, Conceptual basis, mathematical content, and level of detail, we select models that are representative of the range of approaches taken. Six of these are reviewed in detail, and four others are discussed more briefly.We find that the existing literature forces one to choose between tractability and suitability for contemporary urban areas, The key omission in the tractable models is economies of agglomeration that would help explain the emergence of subcenters. Most tractable models also lack a dynamic structure suitable for handling rapid disequilibrium growth." Models that contain these two features are suitable for broad-brush computer simulation: but they cannot be calibrated with real disaggregated land-use data. This conclusion leads to some brief suggestions on directions for future work
Network impacts of changes in the European aviation industry.
Aircraft industry--Europe; Aeronautics, Commercial--Europe; Infrastructure (Economics)--Europe;
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