Risk‐Cost‐Benefit Analysis for Transportation Corridors with Interval Uncertainties of Heterogeneous Data

Access management, which systematically limits opportunities for egress and ingress of vehicles to highway lanes, is critical to protect trillions of dollars of current investment in transportation. This article addresses allocating resources for access management with incomplete and partially relevant data on crash rates, travel speeds, and other factors. While access management can be effective to avoid crashes, reduce travel times, and increase route capacities, the literature suggests a need for performance metrics to guide investments in resource allocation across large corridor networks and several time horizons. In this article, we describe a quantitative decision model to support an access management program via risk‐cost‐benefit analysis under data uncertainties from diverse sources of data and expertise. The approach quantifies potential benefits, including safety improvement and travel time savings, and costs of access management through functional relationships of input parameters including crash rates, corridor access point densities, and traffic volumes. Parameter uncertainties, which vary across locales and experts, are addressed via numerical interval analyses. This approach is demonstrated at several geographic scales across 7,000 kilometers of highways in a geographic region and several subregions. The demonstration prioritizes route segments that would benefit from risk management, including (i) additional data or elicitation, (ii) right‐of‐way purchases, (iii) restriction or closing of access points, (iv) new alignments, (v) developer proffers, and (vi) etc. The approach ought to be of wide interest to analysts, planners, policymakers, and stakeholders who rely on heterogeneous data and expertise for risk management.     

Whither Risk Assessment: New Challenges and Opportunities a Third of a Century After the Red Book

Six multi‐decade‐long members of SRA reflect on the 1983 Red Book in order to examine the evolving relationship between risk assessment and risk management; the diffusion of risk assessment practice to risk areas such as homeland security and transportation; the quality of chemical risk databases; challenges from other groups to elements at the core of risk assessment practice; and our collective efforts to communicate risk assessment to a diverse set of critical groups that do not understand risk, risk assessment, or many other risk‐related issues. The authors reflect on the 10 recommendations in the Red Book and present several pressing challenges for risk assessment practitioners.     

Portfolio Analysis of Layered Security Measures

Layered defenses are necessary for protecting the public from terrorist attacks. Designing a system of such defensive measures requires consideration of the interaction of these countermeasures. In this article, we present an analysis of a layered security system within the lower Manhattan area. It shows how portfolios of security measures can be evaluated through portfolio decision analysis. Consideration is given to the total benefits and costs of the system. Portfolio diagrams are created that help communicate alternatives among stakeholders who have differing views on the tradeoffs between security and economic activity.     

Has Successful Terror Gone to Ground?

This article considers all 87 attacks worldwide against air and rail transport systems that killed at least two passengers over the 30‐year period of 1982–2011. The data offer strong and statistically significant evidence that successful acts of terror have “gone to ground” in recent years: attacks against aviation were concentrated early in the three decades studied whereas those against rail were concentrated later. Recent data are used to make estimates of absolute and comparative risk for frequent flyers and subway/rail commuters. Point estimates in the “status quo” case imply that mortality risk from successful acts of terror was very low on both modes of transportation and that, whereas risk per trip is higher for air travelers than subway/rail commuters, the rail commuters experience greater risk per year than the frequent flyers.     

Spatial Distribution of Flood Risk and Quality of Spatial Management: Case Study in Odra Valley,Poland

This article presents methodological solutions aimed at presenting the spatial distribution of flood risk and quality of spatial management (land use), indicating both those areas used reasonably and those requiring modification. The purpose was to identify key risk areas and risk‐free areas from the point of view of human security and activity on the floodplains, based on the examples of the vicinities of Wroclaw and Raciborz in the Odra Valley, Poland. Due to recent climate change, Poland has suffered the effects of severe flooding (e.g., 1997, 2001, 2010). The analyses conducted were motivated by the European Parliament and Council's recently implemented Directive 2007/60/WE, as well as by the demand for studies for local spatial planning. The analysis indicates that reasonably developed areas do not account for the majority of those studied, making up 36% of the Wroclaw area and 15% of the Raciborz area.     

Assessing Major Accident Risks to Support Land‐Use Planning Using a Severity‐Vulnerability Combination Method: A Case Study in Dagushan Peninsula,China

Major accident risks posed by chemical hazards have raised major social concerns in today's China. Land‐use planning has been adopted by many countries as one of the essential elements for accident prevention. This article aims at proposing a method to assess major accident risks to support land‐use planning in the vicinity of chemical installations. This method is based on the definition of risk by the Accidental Risk Assessment Methodology for IndustrieS (ARAMIS) project and it is an expansion application of severity and vulnerability assessment tools. The severity and vulnerability indexes from the ARAMIS methodology are employed to assess both the severity and vulnerability levels, respectively. A risk matrix is devised to support risk ranking and compatibility checking. The method consists of four main steps and is presented in geographical information‐system‐based maps. As an illustration, the proposed method is applied in Dagushan Peninsula, China. The case study indicated that the method could not only aid risk regulations on existing land‐use planning, but also support future land‐use planning by offering alternatives or influencing the plans at the development stage, and thus further enhance the roles and influence of land‐use planning in the accident prevention activities in China.     

A Decision Framework for Managing Risk to Airports from Terrorist Attack

This article presents an asset‐level security risk management framework to assist stakeholders of critical assets with allocating limited budgets for enhancing their safety and security against terrorist attack. The proposed framework models the security system of an asset, considers various threat scenarios, and models the sequential decision framework of attackers during the attack. Its novel contributions are the introduction of the notion of partial neutralization of attackers by defenders, estimation of total loss from successful, partially successful, and unsuccessful actions of attackers at various stages of an attack, and inclusion of the effects of these losses on the choices made by terrorists at various stages of the attack. The application of the proposed method is demonstrated in an example dealing with security risk management of a U.S. commercial airport, in which a set of plausible threat scenarios and risk mitigation options are considered. It is found that a combination of providing blast‐resistant cargo containers and a video surveillance system on the airport perimeter fence is the best option based on minimum expected life‐cycle cost considering a 10‐year service period.     

Modeling Finite‐Time Failure Probabilities in Risk Analysis Applications

In this article, we introduce a framework for analyzing the risk of systems failure based on estimating the failure probability. The latter is defined as the probability that a certain risk process, characterizing the operations of a system, reaches a possibly time‐dependent critical risk level within a finite‐time interval. Under general assumptions, we define two dually connected models for the risk process and derive explicit expressions for the failure probability and also the joint probability of the time of the occurrence of failure and the excess of the risk process over the risk level. We illustrate how these probabilistic models and results can be successfully applied in several important areas of risk analysis, among which are systems reliability, inventory management, flood control via dam management, infectious disease spread, and financial insolvency. Numerical illustrations are also presented.     

Risk Policies in the United States: Definition and Characteristics Based on a Scoping Review of the Literature

The concept of “risk policy” is used with increasing frequency by decisionmakers, researchers, and the media. However, there is no precise, generally accepted definition of what is covered by policies in this area. Based on a scoping review of the literature published in key journals in the sector, we have identified the main characteristics of public risk policies drawn up and implemented in the United States. The sample comprised 21 articles published in six multidisciplinary journals between 2000 and 2010.