Prospect Theory for joint time and money consequences in risk and ambiguity

Transport users face complex decisions. Not only are the consequences of their choices uncertain, but they generally involve several attributes, such as time and money. Time-money tradeoffs have been studied in depth in transport economics, and research is now paying increasing attention to the role of uncertainty and information in transport decisions. This paper aims to measure the impact of uncertainty and information on multi-attribute decisions using Prospect Theory. In doing so, the study makes two contributions to transportation literature: one methodological and the other empirical. First, we propose a fast and tractable method for measuring Prospect Theory parameters that capture attitudes towards probabilities (probability weighting function) and attitudes towards losses (loss aversion). The elicitation method does not require the elicitation of the utility function. This makes it particularly suitable in complex multi-attribute decisions where the shape of the utility function is unknown. Second, we present the results of an experiment that uses the proposed method to measure, at the individual level, probability weighting in decisions involving joint time and money consequences in two decision contexts: risk (where probabilities are given) and ambiguity (where the probability distribution is unknown). An experimental setup that exposes subjects to real gains and losses for money and time has been built for this purpose. We observe inverse S-shaped probability weighting and loss aversion for risk. Probability weighting is even more pronounced in ambiguity, where subjects do not have precise information about the probability distribution. We explain how these results and the analysis of ambiguity attitudes in general can offer a better understanding of travelers’ route or transport mode choices.     

Risk of increasing temperature due to climate change on high-speed rail network in Spain

With more than 3,200 km of track, the Spanish high-speed rail network is the longest network in Europe and the second largest in the world after China. Due to its geographical location in southern Europe, the entire network is exposed to periods of elevated temperatures that can cause disturbances and severe disruptions such as rail deformation, or in the worst case, lateral track buckling. In this study, the vulnerability of the current Spanish high-speed rail network is analysed in terms of track buckling failures with a Monte Carlo simulation. Downscaled temperature projections from a range of Global Climate Models (GCMs), under three Representative Concentration Pathways (RCP4.5, RCP6.0 and RCP8.5), were forced in a buckling model and particularized for different segments of the network. With that, the proposed methodology provides the number of rail buckles expected per year by assuming current maintenance standards and procedures. The result reveals significant increase in the occurrence of buckling events for future years, mainly in the central and southern areas of mainland Spain. However, relevant variations are found in different climates and time horizon scenarios in Spain. The anticipated buckling occurrences highlight the vulnerability of the Spanish rail network in the context of global warming scenarios. Overall, the proposed methodology is designed to be applicable in large-scale railway networks to identify potential buckling sites for the purpose of understanding and predicting their behaviour.     

Group attitude and hybrid sanctions: Micro-econometric evidence from traffic law

In many legal domains hybrid sanctions – i.e. the joint use of both monetary and non-monetary sanctions – are usually applied. We suggest that one possible rationale behind this form of sanction is targeting group-specific deterrence. For some groups of agents, hybrid sanctions act indeed as a self-selection mechanism such that deterrence is obtained only after a critical threshold of infractions is reached. We apply our model to traffic law infractions and further test it, performing a micro-econometric analysis on a unique dataset of a representative sample of 50,000 Italian drivers, over six years (2003–2009), after the introduction of a penalty points system. Our findings empirically confirm our theoretical predictions. When repeated infractions are at stake, well-designed hybrid sanctions, such as the penalty point system designed for traffic law enforcement, may indeed increase overall deterrence. Our results shed new light on the role of the combined monetary and non-monetary sanctions to perform general and specific deterrence.     

关于船舶签证执法风险的思考

船舶签证是海事管理工作的重要环节,文章从行政不作为、船舶适航性审查、恶劣天气条件影响三个方面分析了船舶签证的执法风险,提出了降低执法风险的几点建议。     

基于蜂窝单元的海上交通风险分析

传统的船舶交通风险分析是将研究水域作为一个整体来评估其风险状况的。基于蜂窝单元的船舶交通风险分析,把研究水域按一定标准划分为若干地理单元,将历史数据、数学模型以及专家学者的经验和判断有机地结合起来,用以评估每一地理单元船舶碰撞和搁浅事故的概率,其输出结果以地理分布的形式突出了高风险区域。相对于传统的风险分析,该理论更能够全面、准确地描述水域的风险状况,为采纳和实施正确的安全措施提供了强有力的支持。     

基于概率影响图的海洋平台安全风险评估方法

本文将概率影响图方法引入海洋平台的安全风险评估，将概率影响图的目标定向与风险分析中的FMEA方法相结合，成功地构造出了系统分析模型。通过关系矩阵的建立和数据结构的定义，实现了对模型结构的动态描述，并应用程序算法，完成了分析推理的全过程。本文以海洋平台作为分析对象，但方法具有普遍的适用性。     

军品型号研制项目的技术风险评估研究

本文重点探讨了武器军品型号研制项目技术风险的概念与内涵,详细介绍一种基于风险因子模糊评价法的技术风险评估模型。作者结合实际案例,应用技术风险评估方法对某型号装置分离系统的研制进行了技术风险分析。     

基于CMD系统进行风险矩阵管理的思考

安全是铁路工作永恒的主题,我国铁路机务信息化建设近几年蓬勃发展,如何利用先进的信息技术手段更好地确保机务生产的安全,是当今急需解决的问题。而CMD系统自身能提供机车实时的动静态数据,结合机务工作风险管理的需要,将风险矩阵的方式应用于机车落地数据进行及时分析估算,可获得机车在途运行过程中的风险点动态,为机务安全生产提供有价值的信息。基于CMD系统,对机务系统实际工作中的一些风险源进行风险矩阵管理的分析,具有一定的理论价值和工程实用意义。     

Confidence bounds on structural reliability estimations for offshore platforms

Second-order estimates to measure platform reliability are generated and used to provide an additional space to select safety margins appropriate to the owner's perception or for risk-averse managers. The aleatory and epistemic uncertainties in the parameters of an offshore platform are explicitly considered in the reliability analysis and the platform structural reliability becomes a random variable, assessing then the beneficial effects of a reduction on these uncertainties. One of these benefits is for risk-aversive managers who often demand additional room to make conservative decisions regarding reliability estimations. Proposed here is a procedure to generate the frequency diagram of platform reliability with the use of confidence bounds to support reliability and cost decisions based on percentiles instead of mean values. The concepts are illustrated through a typical offshore platform in Mexico. The frequency diagram of the platform reliability index is built for several alternative designs and three levels of epistemic uncertainty. The results may be applied for decision making on new designs and also on the assessment and optimal inspection, retrofit, and decommissioning of existing platforms.     

航海风险识别、评估和控制

因航运业高速发展和海员职业流动性加快,导致全球高级船员紧缺,已引发高级船员提升周期缩短、航海经验不足等现象。航海事故造成人员伤亡、财产损失和污染海洋环境等已严重威胁公共安全,航海事故预防和风险控制越来越受到人们关注。船舶海上事故频发,与船员对海上风险,尤其是船员对人为因素与事故的关系的认识不足有关。通过重点介绍航海风险,提高船员对本船和自身存在的风险意识,采取相应的防范措施。