The Value of a Statistical Life in a Road Safety Context — A Review of the Current Literature

Abstract

This paper summarizes the state-of-the-art for assessing the value of a statistical life (VSL) as a component of the costs of road accidents. It focuses on the most popular approaches for assessing the VSL, with respect to its theoretical foundations, current state-of-research and empirical evidence. Our paper also provides a first (to our knowledge) compendium of results for the VSL based on Stated Choice (SC) methods. Among the analysed alternatives, the willingness-to-pay (WTP) appears to be the leading approach for assessing the VSL and the SC methods represent the current state-of-the-art for determining the WTP for non-market goods. We conclude that the SC approach overcomes some of the most important shortcomings of the alternative approaches and offers a significant flexibility that can be used to address its own limitations. We also identify a significant need for research, as a gap between the methods employed in research (SC methods) and the state-of-the-practice (other methods) has emerged.     

Random regret minimization or random utility maximization: an exploratory analysis in the context of automobile fuel choice

Interest in alternative behavioural paradigms to random utility maximization (RUM) has existed ever since the dominance of the RUM formulation. One alternative is known as random regret minimization (RRM), which suggests that when choosing between alternatives, decision makers aim to minimize anticipated regret. Although the idea of regret is not new, its incorporation into the same discrete choice framework of RUM is very recent. This paper is the first to apply the RRM‐model framework to model choice amongst durable goods. Specifically, we estimate and compare the RRM and RUM models in a stated choice context of choosing amongst vehicles fuelled with petrol, diesel and hybrid (associated with specific levels of fuel efficiency and engine capacity). The RRM model is found to achieve a marginally better fit (using a non‐nested test of differences) than its equally parsimonious RUM counterpart. As a second contribution, we derive a formulation for regret‐based elasticities and compare utility‐based and regret‐based elasticities in the context of stated vehicle type choices. We find that in the context of our choice data, mean estimates of elasticities are different for many of the attributes and alternatives. Copyright © 2011 John Wiley & Sons, Ltd.     

Investigating the effect of travel time variability on drivers' route choice decisions in Shanghai,China

Abstract

This paper investigates the effect of travel time variability on drivers' route choice behavior in the context of Shanghai, China. A stated preference survey is conducted to collect drivers' hypothetical choice between two alternative routes with designated unequal travel time and travel time variability. A binary choice model is developed to quantify trade-offs between travel time and travel time variability across various types of drivers. In the model, travel time and travel time variability are, respectively, measured by expectation and standard deviation of random travel time. The model shows that travel time and travel time variability on a route exert similarly negative effects on drivers' route choice behavior. In particular, it is found that middle-age drivers are more sensitive to travel time variability and less likely to choose a route with travel time uncertainty than younger and elder drivers. In addition, it is shown that taxi drivers are more sensitive to travel time and more inclined to choose a route with less travel time. Drivers with rich driving experience are less likely to choose a route with travel time uncertainty.     

Adaptive choice behaviour of motorists in congested shopping centre parking lots

Currently existing models of parking choice behaviour typically focus on the choice of types of parking spaces. Implicitly these models assume that motorists have a free choice in that spaces are available. The adaptive behaviour which they reveal when faced with congested parking spaces is not explicitly modelled. The aim of this paper is to contribute to the growing literature on parking choice modelling by developing and testing a stated choice model of adaptive behaviour of motorists who are faced with fully occupied parking lots. The findings of the analyses indicate that the model performs satisfactory as indicated by its goodness-of-fit and the fact that all significant parameters were in anticipated directions.     

On the semantic scale problem in stated preference rating experiments

Stated preference (SP) rating experiments are easy to design and conduct. Furthermore, they constitute a generalisation of SP choice experiments in terms of the information about preferences that can be achieved. However, its results are sensitive to the numerical values assigned by the analyst to the semantic scale used by individuals to express their preferences. We consider this problem in depth using a variety of statistical techniques, including ordinal probit and a novel optimal scale linear regression approach.     

Preference Heterogeneity and Willingness to Pay for Travel Time Savings

We examined different model specifications to detect the presence of preference heterogeneity in a mode choice context. The specification that worked best allows for both systematic and random variations in tastes, with parameters obtained at the individual level using Bayesian methods. Subjective values of travel time (SVT) and expected individual compensated variation were derived and aggregated to obtain measures of social welfare. Results suggest that the benefit measures, both at the individual and at the social level, are sensitive to preference heterogeneity assumptions. SVT and welfare changes derived from travel time reductions could be underestimated if the traditional assumption of taste homogeneity is made (we detected differences up to 30% in both types of measures). We also obtained an empirical value for the error made when evaluating changes in social welfare using an approximation of the expected individual compensated variation (expressed as a function of individual SVT) rather than its exact expression.     

基于LC-HB模型的铁路货运客户选择偏好差异性与市场细分方法

铁路货运客户自身的选择偏好直接影响对运输服务的选择,进而影响到不同货运服务的市场占有率,而选择偏好性受显性变量和隐性变量的影响。基于随机效用模型,分析铁路货运客户的运输服务选择模式,引入潜类模型,将客户选择偏好纳入先验概率和后验概率模型,并根据客户对服务属性的选择偏好差异性,建立铁路货运市场细分模型。同时,使用叙述性偏好实验,构建铁路货运服务效用模型,通过模拟服务选择过程,获取客户对不同货运服务的选择偏好数据。通过分层贝叶斯与潜类模型,对用户选择效用值和市场细分值进行迭代运算,得到实验样本选择偏好差异性的多元分布函数,及每个市场细分的客户规模、隶属度函数、对服务属性和服务层次的效用值。数据分析表明,客户选择偏好存在明显差异性,同时,解释并验证内生性市场细分方法能够对不同客户群体的隐性变量进行刻画,进而从铁路货运客户选择行为角度划分货运市场。     

Synergetic Optimization of Missile Shapes for Aerodynamic and Radar Cross-Section Performance Based on Multiobjective Evolutionary Algorithm

IntroductionIt is well known that the aerodynamic perfor-mance depends on the shape of missiles. And sodoes the electromagnetic performance( radar- ob-servable) of missiles. The aerodynamic design ofsuch missile must account for high ratio of lift todrag as well as enough stability.As for the elec-tromagnetic performance should be considered,theaerodynamic specialist may have to reconcile therequirements of his best aerodynamic designagainst the electromagnetic requirements of a RCSspecialis…     

超对策模型中结局偏好模糊认知信息的融合

提出了一种新的超对策结局偏好模糊认知信息的融合方法.用一种模糊集结算子来表示专家群体对其他局中人结局偏好的模糊认知,通过求解线性规划模型得到结局偏好群体模糊认知的水平截集;以与模糊数的截集相关的解模糊函数和Newton-Cotes积分公式,得到专家群体对其他局中人结局偏好清晰认知的关系矩阵;运用大多数一致性优胜者模糊集来确定其他局中人的结局偏好向量.给出的数值例子说明了文中提出方法的有效性.     

高速公路可变收费货车出行者出行时间选择模型研究

以效用理论为基础,通过意向调查研究了高速公路货车出行者出行选择模型。针对许多高速公路在高峰时段交通量较大,而其他时段交通量较小的现状,在不同时段采用不同的收费标准,分析可变收费实施后不同属性货车出行者出行选择行为,确定影响出行者出行时间选择的模型变量,得到货车出行者在各水平收费标准时的出行时间选择模型。以京沪高速为实例,设计调查问卷,进行意向调查,通过对调查结果进行分析,选择货车所载货物类型、车货重量作为属性变量,建立了该高速公路货车出行者在两种不同方案下的出行时间选择模型并进行了标定。利用模型标定结果可对可变收费方案进行评价,从而优化可变收费方案,提高高速公路的运行效率。