Is road safety management linked to road safety performance?

This research aims to explore the relationship between road safety management and road safety performance at country level. For that purpose, an appropriate theoretical framework is selected, namely the ‘SUNflower’ pyramid, which describes road safety management systems in terms of a five-level hierarchy: (i) structure and culture, (ii) programmes and measures, (iii) ‘intermediate’ outcomes’ – safety performance indicators (SPIs), (iv) final outcomes – fatalities and injuries, and (v) social costs. For each layer of the pyramid, a composite indicator is implemented, on the basis of data for 30 European countries. Especially as regards road safety management indicators, these are estimated on the basis of Categorical Principal Component Analysis upon the responses of a dedicated road safety management questionnaire, jointly created and dispatched by the ETSC/PIN group and the ‘DaCoTA’ research project. Then, quasi-Poisson models and Beta regression models are developed for linking road safety management indicators and other indicators (i.e. background characteristics, SPIs) with road safety performance. In this context, different indicators of road safety performance are explored: mortality and fatality rates, percentage reduction in fatalities over a given period, a composite indicator of road safety final outcomes, and a composite indicator of ‘intermediate’ outcomes (SPIs). The results of the analyses suggest that road safety management can be described on the basis of three composite indicators: “vision and strategy”, “budget, evaluation and reporting”, and “measurement of road user attitudes and behaviours”. Moreover, no direct statistical relationship could be established between road safety management indicators and final outcomes. However, a statistical relationship was found between road safety management and ‘intermediate’ outcomes, which were in turn found to affect ‘final’ outcomes, confirming the SUNflower approach on the consecutive effect of each layer.     

Safety management by walking around (SMBWA): A safety intervention program based on both peer and manager participation

“Management by walking around” (MBWA) is a practice that has aroused much interest in management science and practice. The purpose of this study is to demonstrate adaptation of this practice to safety management. We describe a three-year long case study that collected empirical data in which a modified MBWA was practiced in order to improve safety in a semiconductor fabrication facility. The main modification involved integrating an information system with the MBWA in order to create a practice that would generate safety leadership development and an organizational safety learning mechanism, while promoting employee safety participation. The results of the case study demonstrate that the SMBWA practice facilitated thousands of tours in which safety leadership behaviors were practiced by managers and by employees (employees performed five times as many tours as managers). The information system collected information about safety behaviors and safety conditions that could not otherwise be obtained. Thus, this study presents a new organizational safety practice SMBWA, and demonstrates the ways in which SMBWA may improve safety in organizations.     

Prospects in fracture mechanics of “engineering” laminates

The test method development for inter-laminar fracture toughness testing of fibre-reinforced composites has yielded one international standard for Mode I opening loading of unidirectionally fibre-reinforced laminates so far. However, the bulk of composite materials in technical applications, summarily labelled “engineering laminates”, mostly consists of laminates with optimised fibre-orientations, frequently varying from ply to ply, i.e., so-called multi-directional laminates. Increasingly, so-called “three-dimensional” laminates are also being developed and being put to use in engineering applications. The present paper explores some of the problems that arise when the standard Mode I test method is applied to engineering laminates in the form of cross-ply (0°/90°) lay-up or z-pin reinforced, three-dimensional composites.     

Interdisciplinary safety analysis of complex socio-technological systems based on the functional resonance accident model: An application to railway trafficsupervision

This paper presents an application of functional resonance accident models (FRAM) for the safety analysis of complex socio-technological systems, i.e. systems which include not only technological, but also human and organizational components. The supervision of certain industrial domains provides a good example of such systems, because although more and more actions for piloting installations are now automatized, there always remains a decision level (at least in the management of degraded modes) involving human behavior and organizations. The field of application of the study presented here is railway traffic supervision, using modern automatic train supervision (ATS) systems. Examples taken from railway traffic supervision illustrate the principal advantage of FRAM in comparison to classical safety analysis models, i.e. their ability to take into account technical as well as human and organizational aspects within a single model, thus allowing a true multidisciplinary cooperation between specialists from the different domains involved.A FRAM analysis is used to interpret experimental results obtained from a real ATS system linked to a railway simulator that places operators (experimental subjects) in simulated situations involving incidents. The first results show a significant dispersion in performances among different operators when detecting incidents. Some subsequent work in progress aims to make these “performance conditions” more homogeneous, mainly by ergonomic modifications. It is clear that the current human-machine interface (HMI) in ATS systems (a legacy of past technologies that used LED displays) has reached its limits and needs to be improved, for example, by highlighting the most pertinent information for a given situation (and, conversely, by removing irrelevant information likely to distract operators).     

Applying MORT to the analysis of the “Tláhuac” incident

The “Tláhuac” incident occurred in Mexico City on 23 November 2004. The fatal incident took place when an angry crowd burnt two police officers alive and seriously injured another after mistaking them for child kidnappers. The third policeman who was finally rescued by colleagues suffered serious injuries. This paper presents some preliminary results of the incident by applying the management over-sight risk tree (MORT) technique. The MORT technique may be regarded as a structured checklist in the form of a complex “fault tree” model that is intended to ensure that all aspects of an organization's management are looked into when assessing the possible causes of an incident. Some other approaches such as a systemic view will be adopted in the future for further analysis. It is hoped that by conducting such analysis lessons can be learnt so that incidents such as the case of “Tláhuac” can be prevented in the future.     

Reliability and risk analysis of large systems with ageing components

Applications of limit reliability functions to the reliability evaluation of large multi-state systems composed of independent components are considered. The main emphasis is on multi-state systems with ageing components because of the importance of such an approach in safety analysis, assessment and prediction, and analysing the effectiveness of operation processes of real technical systems. The results concerned with multi-state series systems are applied to the reliability evaluation and risk function determination of a homogeneous bus transportation system. Results on limit reliability functions of a homogeneous multi-state “m out of n” system are applied to durability evaluation of a steel rope. A non-homogeneous series-parallel pipeline systems composed of several lines of pipe segments is estimated as well. Moreover, the reliability evaluation of the model homogeneous parallel-series electrical energy distribution system is performed.     

Does the concept of safety culture help or hinder systems thinking in safety?

The concept of safety culture has become established in safety management applications in all major safety-critical domains. The idea that safety culture somehow represents a “systemic view” on safety is seldom explicitly spoken out, but nevertheless seem to linger behind many safety culture discourses. However, in this paper we argue that the “new” contribution to safety management from safety culture never really became integrated with classical engineering principles and concepts. This integration would have been necessary for the development of a more genuine systems-oriented view on safety; e.g. a conception of safety in which human, technological, organisational and cultural factors are understood as mutually interacting elements. Without of this integration, researchers and the users of the various tools and methods associated with safety culture have sometimes fostered a belief that “safety culture” in fact represents such a systemic view about safety. This belief is, however, not backed up by theoretical or empirical evidence. It is true that safety culture, at least in some sense, represents a holistic term—a totality of factors that include human, organisational and technological aspects. However, the departure for such safety culture models is still human and organisational factors rather than technology (or safety) itself. The aim of this paper is to critically review the various uses of the concept of safety culture as representing a systemic view on safety. The article will take a look at the concepts of culture and safety culture based on previous studies, and outlines in more detail the theoretical challenges in safety culture as a systems concept. The paper also presents recommendations on how to make safety culture more systemic.     

A safety assessment methodology applied to CNS/ATM-based air traffic control system

In the last decades, the air traffic system has been changing to adapt itself to new social demands, mainly the safe growth of worldwide traffic capacity. Those changes are ruled by the Communication, Navigation, Surveillance/Air Traffic Management (CNS/ATM) paradigm , based on digital communication technologies (mainly satellites) as a way of improving communication, surveillance, navigation and air traffic management services. However, CNS/ATM poses new challenges and needs, mainly related to the safety assessment process. In face of these new challenges, and considering the main characteristics of the CNS/ATM, a methodology is proposed at this work by combining “absolute” and “relative” safety assessment methods adopted by the International Civil Aviation Organization (ICAO) in ICAO Doc.9689 [14], using Fluid Stochastic Petri Nets (FSPN) as the modeling formalism, and compares the safety metrics estimated from the simulation of both the proposed (in analysis) and the legacy system models. To demonstrate its usefulness, the proposed methodology was applied to the “Automatic Dependent Surveillance-Broadcasting” (ADS-B) based air traffic control system. As conclusions, the proposed methodology assured to assess CNS/ATM system safety properties, in which FSPN formalism provides important modeling capabilities, and discrete event simulation allowing the estimation of the desired safety metric.     

Motorcyclists’ speed and “looked-but-failed-to-see” accidents

Previous research on motorcycle crashes has shown the frequency and severity of accidents in which a non-priority road user failed to give way to an approaching motorcyclist without seeing him/her, even though the road user had looked in the approaching motorcycle's direction and the motorcycle was visible. These accidents are usually called “looked-but-failed-to-see” (LBFS) accidents. This article deals with the effects that the motorcyclist's speed has in these accidents. It is based on the in-depth study and precise kinematic reconstruction of 44 accident cases involving a motorcyclist and another road user, all occurring in intersections. The results show that, in urban environments, the initial speeds of motorcyclists involved in “looked-but-failed-to-see” accidents are significantly higher than in other accidents at intersections. In rural environments, the difference in speed between LBFS accidents and other accidents is not significant, but further investigations would be necessary to draw any conclusions. These results suggest that speed management, through road design or by other means, could contribute to preventing “looked-but-failed-to-see” motorcycle accidents, at least in urban environments.     

Modeling of dynamic vehicle–road interactions for safety-related road evaluation

Usually, road safety is assessed by following adequate highway geometric design standards and can be controlled later by measurement and expertise. Nevertheless, interactions between vehicle dynamics and road characteristics cannot be simultaneously analyzed for these two means of safety evaluation. In this study, an analytical method based on road/vehicle physical interactions applied to road diagnosis is proposed. Vehicle “point” and “bicycle” models are used in this first approach. French highway geometric design standards and a statistical method are presented and evaluated on a real curve case. The proposed numerical criterion, for the “bicycle” model, is then compared to these two classical methods for the considered road section. Its advantages are that it takes into account several combined parameters, that road defects are precisely localized and that it provides hierarchically classified solutions to the road managers. After this comparison step, further improvements should be focused on the modeling of successive curves and on the improvement of the informations given to the road manager.     

Incorporating organizational factors into Probabilistic Risk Assessment (PRA) of complex socio-technical systems: A hybrid technique formalization

This paper is a result of a research with the primary purpose of extending Probabilistic Risk Assessment (PRA) modeling frameworks to include the effects of organizational factors as the deeper, more fundamental causes of accidents and incidents. There have been significant improvements in the sophistication of quantitative methods of safety and risk assessment, but the progress on techniques most suitable for organizational safety risk frameworks has been limited. The focus of this paper is on the choice of “representational schemes” and “techniques.” A methodology for selecting appropriate candidate techniques and their integration in the form of a “hybrid” approach is proposed. Then an example is given through an integration of System Dynamics (SD), Bayesian Belief Network (BBN), Event Sequence Diagram (ESD), and Fault Tree (FT) in order to demonstrate the feasibility and value of hybrid techniques. The proposed hybrid approach integrates deterministic and probabilistic modeling perspectives, and provides a flexible risk management tool for complex socio-technical systems. An application of the hybrid technique is provided in the aviation safety domain, focusing on airline maintenance systems. The example demonstrates how the hybrid method can be used to analyze the dynamic effects of organizational factors on system risk.     

Junction formation of CuInSe2 with CdS: A comparative study of “dry” and “wet” interfaces

The junction formation of polycrystalline CuInSe₂ absorbers (CIS) with thermally evaporated CdS was investigated by high-resolution synchrotron X-ray photoelectron spectroscopy. The chemistry and electronics of the interfaces of Cd partial electrolyte treated CIS (“wet” processed) and clean, decapped CIS (“dry” processed) were compared. A valence band offset of 0.96(10) eV was determined in both cases. The Cd(Se,OH) surface layer induced by the wet Cd partial electrolyte process does not significantly modify the band alignment at the CIS/CdS heterointerface from the “dry”, vacuum-processed CIS/CdS interface.During the stepwise interface formation the energy converting capability of the CIS/CdS heterojunction was assessed by in situ surface photovoltage measurements at room temperature. The evolution of the surface photovoltage significantly differs for the “wet” and the “dry” interfaces and is discussed in relation to the function in solar cell devices.     

An integrated approach to evaluate policies for controlling traffic law violations

Modeling dynamics of the driver behavior is a complex problem. In this paper a system approach is introduced to model and to analyze the driver behavior related to traffic law violations in the Emirate of Abu Dhabi. This paper demonstrates how the theoretical relationships between different factors can be expressed formally, and how the resulting model can assist in evaluating potential benefits of various policies to control the traffic law violations Using system approach, an integrated dynamic simulation model is developed, and model is tested to simulate the driver behavior for violating traffic laws during 2002-2007 in the Emirate of Abu Dhabi. The dynamic simulation model attempts to address the questions: (1) “what” interventions should be implemented to reduce and eventually control traffic violations which will lead to improving road safety and (2) “how” to justify those interventions will be effective or ineffective to control the violations in different transportation conditions. The simulation results reveal promising capability of applying system approach in the policy evaluation studies.     

The next generation of macroergonomics: Integrating safety climate

To date little research has examined safety climate in relation to macroergonomics and how the two distinct sub-disciplines can be integrated to affect safety outcomes. The purpose of macroergonomics is to design a fully “harmonized” work system that improves numerous aspects of organizational performance and effectiveness, and this is accomplished by incorporating the foundational theoretical framework of sociotechnical systems theory (STS). Two broad subsystems within such a system are the personnel subsystem, the ways individuals perform tasks, and the technological subsystem, the tasks to be performed. Management is an important aspect of the personnel subsystem, and there is a growing body of research regarding supervisors’ influence over employee safety. One such area of research is safety climate, which is based on the perception of workers regarding safety and organizational practices. Two major factors of safety climate are management commitment to safety and communication pertaining to safety as a true priority from both top management and direct supervisors. This article describes the conceptual overlaps of macroergonomics and safety climate in order to present a conceptual model that integrates these domains using the framework of mesoergonomics. In conclusion, we discuss how this model can serve as a framework to guide the analysis and design of work systems and subsequent organizational interventions.     

The ‘PROCESO’ index: a new methodology for the evaluation of operational safety in the chemical industry

The acknowledgement of industrial installations as complex systems in the early 1980s outstands as a milestone in the path to operational safety. Process plants are social–technical complex systems of a dynamic nature, whose properties depend not only on their components, but also on the inter-relations among them. A comprehensive assessment of operational safety requires a systemic approach, i.e. an integrated framework that includes all the relevant factors influencing safety. Risk analysis methodologies and safety management systems head the list of methods that point in this direction, but they normally require important plant resources. As a consequence, their use is frequently restricted to especially dangerous processes often driven by compliance with legal requirements. In this work a new safety index for the chemical industry, termed the ‘Proceso’ Index (standing for the Spanish terms for PROCedure for the Evaluation of Operational Safety), has been developed. PROCESO is based on the principles of systems theory, has a tree-like structure and considers 25 areas to guide the review of plant safety. The method uses indicators whose respective weight values have been obtained via an expert judgement technique. This paper describes the steps followed to develop this new Operational Safety Index, explains its structure and illustrates its application to process plants.     

Multifunctional surface structures of plants: An inspiration for biomimetics

Biological surfaces provide multifunctional interfaces to their environment. More than 400 million years of land plants evolution led to a large diversity of functional biological surface structures. This article provides an overview of the most frequently functional surface structures of plants. It focuses on functional adaptations of plant surface structures to environmental conditions. The structural and functional relationships of plants growing in deserts, water and wetlands are discussed. The article is written for both biologists and non-biologists and should stimulate the readers to initiate or intensify the study of functional biological surfaces and their potential for technical use, leading to, so called, biomimetic inspired smart surfaces. For a broader understanding of the structural diversity in plants, the origin of surface structuring is introduced from the sub-cellular level up to multi-cellular structures. Functional aspects of plant surface structures include the reduction of particle adhesion and the self-cleaning properties in the Lotus (Nelumbo nucifera) leaves. These surface properties are based on physico-chemical principles and can be transferred into technical “biomimetic” materials, as successfully done for the Lotus leaves. In plants, several other functional structures, e.g., for the absorption of water or light reflection, exist. Some, which might be useful models for the development of functional materials, are introduced here and some existing technical applications and fabrication techniques for the generation of biomimetic surfaces are discussed.     

From mono- to polytopic interactions via hydrogen bonds — Capacitive sensor studies

Supra molecular materials can be generated via hydrogen bonding between monomers. This leads either to “monotopic” molecules as well as self-assemblies of a restricted number of complementary components as “di-” or “polytopic” molecules with more than one functional unit. The latter structures grow spontaneously by self organization and in principle consist of repeatedly branched chain molecules analogous to dendrimers. When disturbing these aggregates by analyte molecules (e.g. volatile organic compounds), the supra molecular structures break down leading to a pronounced change in dielectric behavior that is detectable with inter digital capacitors. “Monotopic”-materials show linear behavior with increasing analyte concentration whereas “polytopic” molecules lead to properties resembling a threshold sensor.     

A Strip-Yield algorithm for the analysis of closure evaluation near the crack tip

“Plasticity-induced crack closure” phenomenon is the leading mechanism of different effects (R-ratio, overload retardation, … ) acting on crack growth rate in many metallic materials. Experimental tests are carried out to quantify the physical phenomenon, while Strip-Yield analytical models have been developed for predicting life of components. In the present work, an additional module to be applied to a Strip-Yield model is proposed in order to derive the strains near the crack tip. Particularly, the module is based on the Westergaard’s elastic complex potential. The presented algorithm allowed us to obtain the correlation between “local compliance” experimental results and the corresponding Strip-Yield analyses. This method can be taken as a semi-analytical procedure for calibrating the constraint factor, i.e., the most delicate parameter for Strip-Yield models.     

Spectroscopic ellipsometry analyses of thin films in different environments: An innovative “reverse side” approach allowing multi angle measurements

An innovative ellipsometer sample holder has been designed and tested in order to measure thin films optical properties under different environments and so infer the porosity through effective medium approximation models. Compared to commercial cells that require a fixed angle of incidence or a cell with a cylindrical geometry, we present a simple cell in which the sample is mounted in “reverse side”, allowing multiple angle analyses without the need for cell windows. Standard ellipsometry measurements are compared to the “reverse side” approach in order to confirm the feasibility of this new procedure, obtaining the same refractive index dispersion curves in both cases. Then different samples have been tested in “reverse side” under different environments to measure porosity. The multiangle approach has been found useful to improve the fitting of the experimental data by reducing both the fitting error and the correlation between parameters.