Transportation Network Data Requirements for Assessing Criticality for Resiliency and Adaptation Planning

This report is one of two NCST Research Report documents produced as part of a project to advance the technical modeling tools for resiliency and adaptation planning, especially those used for criticality rankings. The official final technical report, Climate Adaptation and Resiliency Planning: Agency Roles and Workforce Development Needs, summarizes a climate adaptation framework and describes current planning practices and workforce needs of Departments of Transportation and other planning agencies. This additional technical documentation report looks specifically at the network data challenges of objectively assessing asset criticality, one step in the larger adaptation planning framework and a prerequisite for efficient allocation of limited adaptation resources. Specifically, this report explores the modeling resolution (in terms of the completeness of the road network and the spatial disaggregation of origin and destination matrices) needed to produce accurate criticality ratings. Original modeling work using a well-establish criticality measure, the Network Robustness Index (NRI), on both a small hypothetical network and the road network for Chittenden County, Vermont, demonstrated a need for higher resolution networks for criticality modeling. Since this part of the work was published in the Transportation Research Record it is only summarized here. A conceptual discussion of methods explored for creating networks for larger real-world areas that are sufficiently complete for criticality assessment is also included based on exploratory work using the travel demand model for the Greater Sacramento California area.View the NCST Project Webpag

Novel approach to transport project appraisal: Demand weighted multi-modal level of service

© 2018 Transportation Systems in the Connected Era - Proceedings of the 23rd International Conference of Hong Kong Society for Transportation Studies, HKSTS 2018. All rights reserved. Traffic management, road network planning and appraisal are highly dependent on effectively assessing the performance of existing and future road infrastructure. In traffic engineering, performance assessment has been underpinned by a grading system known as the “Level of Service” (LoS), which identifies performance criteria that reflects the functionality of the road. This study develops a novel, consistent calculation methodology, the Demand Weighted Level of Service Estimation (DWLE) method, to estimate singular holistic multi-modal LoS metrics, which can be used to compare and contrast the performance of road segments. The generalized approach is independent of the definition and quantification of LoS indicators which offers global application potential. A demonstration of the approach provides evidence for the robustness and consistency of the approach. The value of the DWLE method is that it offers a tool for project prioritization evolving a long-held traffic engineering concept of the Level of Service

Modelling project feasibility robustness by use of scenarios

Key words: Evaluation, Scenario, Uncertainty, Multi-Modal Abstract: This paper presents the application of a new scenario based analysis technique which has been developed for transport infrastructure planning. The approach aims at dealing with uncertainty in the planning environment in a more systematic way than is usually the case when applying scenario analysis. Specifically, the developed scenario approach secures a consistent inclusion of actual scenario elements in the quantitative impact modelling and facilitates a transparent project feasibility robustness analysis. The approach has been implemented in a SCENARIO MANAGER as part of an infrastructure planning decision support system which comprises GIS-related impact models embedded in a tool-box applicable to multi-modal transport investment analysis. Following a brief introduction, the next section of the paper outlines a conceptual scenario model which categorises project uncertainties into three main groups: Objective, adaptive and subjective uncertainty. This model illustrates the correlation between the scenario definition and the uncertainty in the planning environment. This scenario approach distinguishes itself from usual single dominant issue scenarios or prognoses as it is based on thematic scenario writing. In the case presented, four scenarios are introduced which have been developed in a recent Danish scenario study: (I) the market-oriented society, (II) the locally-oriented society, (III) the supra-national society and (IV) the technological society. Each scenario is then analysed as concerns its impact on a set of relevant project evaluation criteria. The criteria used stem from the on-going EUNET project funded by the European Commission DGVII, within the Strategic Transport part of the Fourth Framework Programme. Section three of the paper demonstrates the application of the systematic scenario analysis technique by means of a case study. The case concerns multi-modal evaluation of the Harbour Tunnel under the Copenhagen harbour. One-third of central Copenhagen is divided from the rest by the harbour. Presently, the harbour has four road bridge crossings and one rail bridge crossing. The investment in question concerns a fifth road tunnel at the entrance of the harbour, which aims at forming a complete high standard road systems around Copenhagen while at the same time reducing the environmental impacts to the medieval town centre. Four different solutions to the inclusion of the new Harbour Tunnel in the road network are examined. The concept of scenario profiling is introduced, which in an operational manner examines the project robustness related to each of the four project alternatives. The scenario profile gives a comprehensive description of the scenario implications for the socio-economic feasibility of each project alternative. Through a systematic, scenario based set of weights, the overall project robustness is determined. The final section five presents conclusions and recommendations. It is stated that the scenario approach presented is a valuable aid in assisting decision making on transport investment planning. The area for future research into the further integration of model uncertainty with scenario based robustness evaluations, is outlined.

An indexing model for stormwater quality assessment: stormwater management in the Gold Coast

In the age of climate change and rapid urbanisation, stormwater management and water sensitive urban design have become important issues for urban policy makers. This paper reports the initial findings of a research study that develops an indexing model for assessing stormwater quality in the Gold Coast

Investigation of air transportation technology at Princeton University, 1991-1992

The Air Transportation Research Program at Princeton University proceeded along six avenues during the past year: (1) intelligent flight control; (2) computer-aided control system design; (3) neural networks for flight control; (4) stochastic robustness of flight control systems; (5) microburst hazards to aircraft; and (6) fundamental dynamics of atmospheric flight. This research has resulted in a number of publications, including archival papers and conference papers. An annotated bibliography of publications that appeared between June 1991 and June 1992 appears at the end of this report. The research that these papers describe was supported in whole or in part by the Joint University Program, including work that was completed prior to the reporting period

A network approach for power grid robustness against cascading failures

Cascading failures are one of the main reasons for blackouts in electrical power grids. Stable power supply requires a robust design of the power grid topology. Currently, the impact of the grid structure on the grid robustness is mainly assessed by purely topological metrics, that fail to capture the fundamental properties of the electrical power grids such as power flow allocation according to Kirchhoff's laws. This paper deploys the effective graph resistance as a metric to relate the topology of a grid to its robustness against cascading failures. Specifically, the effective graph resistance is deployed as a metric for network expansions (by means of transmission line additions) of an existing power grid. Four strategies based on network properties are investigated to optimize the effective graph resistance, accordingly to improve the robustness, of a given power grid at a low computational complexity. Experimental results suggest the existence of Braess's paradox in power grids: bringing an additional line into the system occasionally results in decrease of the grid robustness. This paper further investigates the impact of the topology on the Braess's paradox, and identifies specific sub-structures whose existence results in Braess's paradox. Careful assessment of the design and expansion choices of grid topologies incorporating the insights provided by this paper optimizes the robustness of a power grid, while avoiding the Braess's paradox in the system.Comment: 7 pages, 13 figures conferenc