||Transport Assessment and Risk Analysis: The Case of the 2nd Fixed Link across the Dunabe River
||Mudova, Nedyalka Dimitrova
||Leleur, Steen (Decision Modelling, Department of Transport, Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark)
Salling, Kim Bang (Decision Modelling, Department of Transport, Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark)
||Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark
The main purpose of this Master Thesis project is to present an appraisal study of the second fixed link across the Danube River between Vidin (Bulgaria) and Calafat (Romania) by the use of the CBA-DK model. The evaluation model consists of two modules – deterministic, which includes the cost-benefit analysis, and stochastic or so called Risk analysis module. The feasibility risk adopted in the model is based on assigning probability distributions to the uncertain model parameters. Two probability distributions has been determined suitable for the available data, the PERT and Erlang, respectively assigned to the travel time savings and the construction cost. The results aim to provide better information for the decision-makers based on consideration of the desired level of risk regarding the feasibility risks.
The paper investigates the latter two impacts in terms of the Optimism Bias principle which is used to take account of the underestimation of construction costs and the overestimation of travel time savings. By extending this principle into stochastic modelling in terms of quantitative risk analysis (QRA), so-called feasibility risk assessment is provided by moving from point (deterministic CBA) to interval (stochastic QRA) results. Hereby, decision support as illustrated in this paper will aim to provide assistance in the development and ultimately the choice of action, while accounting for the uncertainties surrounding transport appraisal schemes.
This paper applies quantitative risk analysis (QRA) and Monte Carlo simulation, which is very similar to a traditional sensitivity analysis, as it generates a number of possible scenarios. Hence, the procedure effectively accounts for the two input uncertainties of “what if” scenarios and Optimism Bias. The simulation procedure then goes one step further by generating a large set of values that each input variable can take and weighs each scenario by the probability of occurrence. Consequently, instead of receiving single point results, it is received interval results in terms of an output probability distribution.
The Decision support system named COSIMA-DSS, based on the combination between the cost-benefit analysis with multi-criteria analysis and quantitative risk analysis is presented in the following Master Thesis project. The model is used to evaluate both traditional monetary and non-monetary impacts such as environment, economic growth in the region, integration, accessibility, landscape and urban development. The uncertainty concerning the deterministic point results are treated with Monte Carlo simulation.
The paper will be structured as follows. The decision support model of CBA-DK is presented together with the case study as depicted. The model consists of the two types of analyses, as described above, resulting in feasibility risk assessment (FRA). For each method a sub-section in the paper is provided, together with detailed definitions all relating to the case study of the fixed link connection of Danube River. The Optimism Bias approach embedded within the deterministic calculations is then presented, together with conclusions and a more general discussion of the results. Finally, the decision support modelling system COSIMA is applied to the studied project.
||Technical University of Denmark (DTU) : Kgs. Lyngby, Denmark
Creation date: 2010-01-06
Update date: 2010-01-06