Validating self-reported driving behaviours as determinants of real-world driving speeds.

Self-reported driver behaviour has long been a tool used by road safety researchers to classify drivers and to evaluate the impact of interventions yet the relationship with real-world driving is challenging to validate due to the need for extensive, detailed observations of normal driving. This study examines this association by applying the large UDRIVE naturalistic driving study data involving 96 car drivers, comprising 131,462 trips and 1,459,110 km travelled over a duration of 32,096 hours, to compare individual questions and composite indicators based on the Driver Behaviour Questionnaire with real world driving. Self-reported speed behaviour was compared to the measured values under urban and highway conditions. Generalised Linear Mixed Models were developed to examine the relationships between the observed speed behaviours with DBQ errors and violations scores in conjunction with traffic and environmental factors. Drivers' self-reported data on speed selection seldom aligned with their real-world behaviour and there were no meaningful differences between many of the response categories. The DBQ violations and errors scales showed a highly significant correlation with driving speed indicators however they had a low explanatory power compared to other traffic situational and driving factors. Overall, the study highlights the need to validate self-reported driving data against the accuracy and relevance to real-world driving.

Self-reports of driving behaviour have long been a tool in road safety research and evaluation yet responses on speed selection are commonly inaccurate and may have little relation with real-world driving.

Decline in Traffic Congestion Increased Crash Severity in the Wake of COVID-19.

Highway fatalities are a leading cause of death in the U.S. and other industrialized countries. Using highly detailed crash, speed, and flow data, we show highway travel and motor vehicle crashes fell substantially in California during the response to the COVID-19 pandemic. However, we also show the frequency of severe crashes increased owing to lower traffic congestion and higher highway speeds. This "speed effect" is largest in counties with high pre-existing levels of congestion, and we show it partially or completely offsets the "VMT effect" of reduced vehicle miles traveled on total fatalities. During the first eleven weeks of the COVID-19 response, highway driving decreased by approximately 22% and total crashes decreased by 49%. While average speeds increased by a modest 2 to 3 mph across the state, they increased between 10 and 15 mph in several counties. The proportion of severe crashes increased nearly 5 percentage points, or 25%. While fatalities decreased initially following restrictions, increased speeds mitigated the effect of lower vehicle miles traveled on fatalities, yielding little to no reduction in fatalities later in the COVID period.

Bioprotection of Transportation and Facilities from SARS-CoV-2 (COVID-19).

The recent COVID-19 pandemic has led to a nearly world-wide shelter-in-place strategy. This raises several natural concerns about the safe relaxing of current restrictions. This article focuses on the design and operation of heating ventilation and air conditioning (HVAC) systems in the context of transportation. Do HVAC systems have a role in limiting viral spread? During shelter-in-place, can the HVAC system in a dwelling or a vehicle help limit spread of the virus? After the shelter-in-place strategy ends, can typical workplace and transportation HVAC systems limit spread of the virus? This article directly addresses these and other questions. In addition, it also summarizes simplifying assumptions needed to make meaningful predictions. This article derives new results using transform methods first given in Ginsberg and Bui. These new results describe viral spread through an HVAC system and estimate the aggregate dose of virus inhaled by an uninfected building or vehicle occupant when an infected occupant is present within the same building or vehicle. Central to these results is the derivation of a quantity called the "protection factor"-a term-of-art borrowed from the design of gas masks. Older results that rely on numerical approximations to these differential equations have long been lab validated. This article gives the exact solutions in fixed infrastructure for the first time. These solutions, therefore, retain the same lab validation of the older methods of approximation. Further, these exact solutions yield valuable insights into HVAC systems used in transportation.

Development of a Metric Concept that Differentiates Between Normal and Abnormal Operational Aviation Data.

There is a strong and growing interest in using the large amount of high-quality operational data available within an airline. One reason for this is the push by regulators to use data to demonstrate safety performance by monitoring the outputs of Safety Performance Indicators relative to targeted goals. However, the current exceedance-based approaches alone do not provide sufficient operational risk information to support managers and operators making proximate real-time data-driven decisions. The purpose of this study was to develop and test a set of metrics which can complement the current exceedance-based methods. The approach was to develop two construct variables that were designed with the aim to: (1) create an aggregate construct variable that can differentiate between normal and abnormal landings (row_mean); and (2) determine if temporal sequence patterns can be detected within the data set that can differentiate between the two landing groups (row_sequence). To assess the differentiation ability of the aggregate constructs, a set of both statistical and visual tests were run in order to detect quantitative and qualitative differences between the data series representing two landing groups prior to touchdown. The result, verified with a time series k-means cluster analysis, show that the composite constructs seem to differentiate normal and abnormal landings by capturing time-varying importance of individual variables in the final 300 seconds before touchdown. Together the approaches discussed in this article present an interesting and complementary way forward that should be further pursued.

Progressing the aerospace performance factor toward nonlinear interactions.

Evaluation of safety performance remains central to any safety and risk management. Currently, there are very few support tools and methods which allow for quantitative approach in this domain. One of the successful methods available to this end is the Aerospace Performance Factor (APF). The method is based on hierarchical clustering of taxonomy-based safety performance indicators, using simple and intelligible formula to compute the overall safety performance signal. The work presented in this study deals with one of the APF shortcomings, namely the absence of nonlinear relations among the performance indicators to capture more accurately the risk in the assessed system. It proposes an addition of new decision criteria behind the APF method as part of the application of Analytical Hierarchy Process (AHP), namely the impact of respective performance indicator on other indicators, regardless of their hierarchical structure. This addition leads to relative changes of performance indicators significance, where those with the highest potential for nonlinear interactions among the entire set of performance indicators are emphasized and the change in their weight ultimately leads to changes in the overall APF signal. The study results indicate that the extended APF signal is refined in terms of extremes and it draws more accurate picture about the actual safety performance, eventually supporting better identification of deviations from its acceptable values. The study was experimentally carried out in the aviation with data from the European Central Repository (ECR) originating from United Kingdom during the years 2013-2015 and verified further on data sets from Finland and Denmark.

Nanophase-Separated, Elastic Epoxy Composite Thin Film as an Electrolyte for Stable Lithium Metal Batteries.

The design of solid polymer electrolytes (SPE) with high ionic conductivity and excellent mechanical properties is challenging because these two properties are often conflicting. To achieve both, a reaction-controlled strategy is proposed based on the nanophase separation of an ionic transport pathway and a supporting matrix to balance ionic mobility and mechanical properties. Specifically, an elastic epoxy polymer electrolyte (eEPE), synthesized via two-step polymerization, combines outstanding mechanical strength (toughness of 3.4 MJ m-3) and high ionic conductivity (3.5 × 10-4 S cm-1 at 25 °C). The nanostructured eEPE is both tough and flexible, therefore promotes uniform deposition of Li even under a high current density (2 mA cm-2 and 2 mAh cm-2). Importantly, eEPE composite films greatly improve the safety performance of the LiFePO4/Li pouch cells: safe operations are achieved under several abusive conditions. This work highlights an alternative route for high-safety solid-state lithium metal batteries of the next generation.

[Hospital Safety Climate: Concept and Measurement Tools].

Work environments at healthcare organizations involve biological, chemical, and physical risks. Healthcare providers adhere to safe work practices and promote organizational activities proactively to improve practice safety and patient safety, both of which are closely linked to quality of care. In light of the limited research on safety culture and employee safety performance in the healthcare industry, this paper was developed to introduce the concept of hospital safety climate; the factors known to influence the safety climate in hospitals and safety performance and outcomes; and related safety climate measurement tools from the perspective of promoting safe performance among hospital healthcare providers. We recommend management create a safe work environment to reinforce employees' positive perceptions about the commitment of management to safety and subsequently promote shared beliefs regarding workplace safety and motivate employees to create a safer work environment. In addition, healthcare providers' perceptions of the safety climate should be assessed to identify strengths and weaknesses in the safety climate, guide the development of related improvement measures, and enhance the safety-climate perceptions of employees.

BIM and Computer Vision-Based Framework for Fire Emergency Evacuation Considering Local Safety Performance.

Fire hazard in public buildings may result in serious casualties due to the difficulty of evacuation caused by intricate interior space and unpredictable development of fire situations. It is essential to provide safe and reliable indoor navigation for people trapped in the fire. Distinguished from the global shortest rescue route planning, a framework focusing on the local safety performance is proposed for emergency evacuation navigation. Sufficiently utilizing the information from Building Information Modeling (BIM), this framework automatically constructs geometry network model (GNM) through Industry Foundation Classes (IFC) and integrates computer vision for indoor positioning. Considering the available local egress time (ALET), a back propagation (BP) neural network is applied for adjusting the rescue route according to the fire situation, improving the local safety performance of evacuation. A campus building is taken as an example for proving the feasibility of the framework proposed. The result indicates that the rescue route generated by proposed framework is secure and reasonable. The proposed framework provides an idea for using real-time images only to implement the automatic generation of rescue route when a fire hazard occurs, which is passive, cheap, and convenient.

Exercise heat acclimation causes human responses and safety performance improvements.

Heat acclimation (HA) is a widely recognized physiological phenomenon of human body in hot environments. HA has many benefits, such aspreventing hyperthermia responses, and is an efficient way to improve human responses to hyperthermal environments. However, it is not known whether HA is dependent on the environmental conditions. Moreover, its mechanism and effect on the safety performance remain unexplored. In this study, we created a climate chamber to simulate a hyperthermal environment. Thirty healthy males were recruited for this study, who were then trained under the same ambient conditions (temperature of 38 °C and relative humidity (RH) of 40%). The training involved running on treadmills (at 5 km/h) to simulate heavy manual labor, and performing heat stress tests (HST) under six different conditions (32 °C/40% RH, 35 °C/40%, 38 °C/40%, 32 °C/70%, 35 °C/70%, and 38 °C/70%). Their physiological indices (rectal temperature, heart rate, sweat loss and skin temperature) and one psychological index (thermal sensation) were measured. Furthermore, a hazard avoidance test device (HATD) was designed to evaluate the individual safety performance by detecting human errors. The results show that training and environmental conditions have different effects on HA. After HA, the physiological and psychological strain were significantly improved. More importantly, HA also helped improve the participants' awareness of the dangers and required emergency responses to face potential hazards. Overall, a reasonable HA training under proper conditions is helpful to ensure the safety of human beings. More research is needed to study the role of HA on safety performance.

Relationship between patient safety culture and safety performance in nursing: The role of safety behaviour.

AIM: The aim of this work is to test the mediator role of patient safety behaviour between safety culture and safety performance among nurses. METHODS: This cross-sectional study was carried out between September and December 2017 in the nursing units of 10 primary hospitals, two secondary hospitals and two tertiary hospitals in Anhui Province, China. RESULTS: The study participants comprised 79 RNs from primary hospitals, 147 RNs from secondary hospitals and 242 RNs from tertiary hospitals. Most were female (97.6%) and married (73.1%), and their ages ranged from less than 25 years to retirement age. The sample included nurses working in several departments, including medicine (27.1%), surgery (14.3%), emergency (11.5%) and ICU (9%). Structural equation model analysis results showed that espoused values directly affected safety performance, and practised values affected safety performance through safety behaviour. CONCLUSION: Our hypothetical model noted that safety behaviour is a positive mediating factor of practised safety values affecting safety performance, suggesting that Chinese nursing managers should construct a patient safety culture that is guided and driven by appropriate values, which will ultimately be externalized as nurses' daily behaviour.

Predicting hospitality employees' safety performance behaviors in the COVID-19 pandemic.

This study develops and tests a research model to explain and predict how and when organizational safety climate influences hospitality employees' safety performance behaviors by proposing two boundary conditions: communication transparency and safety-related stigma based on expectancy-valence theory. Specifically, we examined if communication transparency intensifies the impact of perceived safety climate on employees' safety motivation that drives safety performance behaviors through prevention work focus and if safety-related stigma attenuates the links between safety motivation and safety performance behaviors. Based on two national samples of 214 South Korean and 240 U.S. foodservice employees, this research found that safety climate was positively associated with safety motivation, prompting safety behaviors with the key mediating mechanism of prevention focus work. However, there were different patterns observed for the moderating roles of communication transparency and stigma for the foodservice employees between South Korea and the United States. Implications of the findings are discussed for hospitality researchers and practitioners.

The Boundary of Lithium Plating in Graphite Electrode for Safe Lithium-Ion Batteries.

Uncontrolled Li plating in graphite electrodes endangers battery life and safety, driving tremendous efforts aiming to eliminate Li plating. Herein we systematically investigate the boundary of Li plating in graphite electrode for safe lithium-ion batteries. The cell exhibits superior safety performance than that with Li dendrites by defining the endurable amount of uniform Li plating in graphite anode. The presence of "dead Li" can be eliminated owing to the uniform distribution of Li plating, and the average Coulombic efficiency for deposited Li during reversible plating/stripping process is decoupled as high as about 99.5 %. Attributing to the limited Li plating with superior Coulombic efficiency, the LiNi0.5 Mn0.3 Co0.2 O2 | graphite cell achieves a high capacity retention of 80.2 % over 500 cycles. This work sheds a different light on further improving the fast-charging capability, low-temperature performance, and energy density of practical lithium-ion batteries.

Impact on Road Safety and Operation of Rerouting Traffic in Rural Travel Time Information System.

The Travel Time Information System (TTIS) is an Intelligent Traffic Control System installed in Poland. As is common, travel time is the only factor in the decision about rerouting traffic, while a route recommendation may consider multiple criteria, including road safety. The aim of the paper is to analyze the safety level of the entire road network when traffic is rerouted on paths with different road categories, intersection types, road environments, and densities of access points. Furthermore, a comparison between traffic operation and road safety performance was carried out, considering travel time and delay, and we predicted the number of crashes for each possible route. The results of the present study allow for maximizing safety or traffic operation characteristics, providing an effective tool in the management of the rural road system. The paper provides a methodology that can be transferred to other TTISs for real-time management of the road network.

Safety Evaluation and Experimental Study of a New Bionic Muscle Cable-Driven Lower Limb Rehabilitation Robot.

Safety is a significant evaluation index of rehabilitation medical devices and a significant precondition for practical application. However, the safety evaluation of cable-driven rehabilitation robots has not been reported, so this work aims to study the safety evaluation methods and evaluation index of cable-driven rehabilitation robots. A bionic muscle cable (BM cable) is proposed to construct a bionic muscle cable-driven lower limb rehabilitation robot (BM-CDLR). The working principle of the BM-CDLR is introduced. The safety performance factors are defined based on the mechanical analysis of the BM-CDLR. The structural safety evaluation index and the use safety evaluation index of the BM-CDLR are given by comprehensively considering the safety performance factors and a proposed speed influence function. The effect of the structural parameters of the elastic elements in the BM cable on the safety performance factors and safety of the BM-CDLR is analyzed and verified by numerical simulations and experimental studies. The results provide the basis for further study of the compliance control strategy and experiments of the human-machine interaction of the BM-CDLR.

When safety climate is not enough: Examining the moderating effects of psychosocial hazards on nurse safety performance.

AIM: To examine the association between components of safety climate and psychosocial hazards with safe work behaviours and test the moderating effects of psychosocial hazards on the safety climate-safety performance relationships. BACKGROUND: The effects of a strong safety climate on safety performance are well cited, however, the conditions that have an impact on this relationship warrant attention. While the psychosocial hazards commonly reported by nurses are predictors of well-being and job attitudes, evidence suggests that these may also place boundaries on the effects of safety climate on safe work practices. DESIGN: This study used a cross-sectional design to collect data from 146 nurses. METHODS: Participants were recruited through convenience sampling and snowball sampling methods in 2017. Nurses completed an online questionnaire and received a $5 e-gift card as compensation. SPSS v.23 and PROCESS v3.0 were used to analyse the data. RESULTS/FINDINGS: A strong safety climate was positively associated with nurses' safety performance. While psychosocial hazards did not predict safety performance, they did moderate the safety climate-performance relationship. High levels of perceived stressors weakened the association between promoting two-way safety communication, the use and implementation of procedures to promote safe work practices and management's endorsement of health and safety with safe work performance. CONCLUSION: The positive effects of safety climate on nurses' safety performance are contingent on the levels of psychosocial hazards nurses experience. When aiming to improve safety performance among nurses, it is important for efforts to also focus on the psychosocial conditions of the work environment.

Work support, psychological well-being and safety performance among nurses in Hong Kong.

This study investigated the mediating role of psychological well-being between work support and safety performance of 314 Hong Kong nurses, using self-reported questionnaires. Results showed that psychological well-being mediated the effects of work support on safety performance. The findings illustrate that work support was an important element to improve psychological well-being. This could generate better safety performance of the nurses. Implications and limitations are discussed.

Job autonomy, perceptions of organizational policy, and the safety performance of nurses.

AIMS: This study aimed to identify the relationship between nurses' job autonomy, perceptions of organizational policy, and safety performance by identifying the safety performance predictors of nurses working in acute health care settings in South Korea. METHODS: Using data from a structured questionnaire, this cross-sectional descriptive study assessed the relationship between nurses' job autonomy, perceptions of organizational policy, and safety performance. In 2016, of the 290 nurses from nine acute care hospitals in South Korea invited to participate in the survey, 254 successfully did. Using cross-sectional data, characteristics of hospitals and nurses were analysed with t tests, one-way analyses of variance, Pearson correlations, and regression models. RESULTS: On a scale of one to five, the mean job autonomy was 3.37, mean perceptions of organizational policy was 3.09, and mean safety performance was 3.75. Statistically significant positive correlations were found among job autonomy, perceptions of organizational policy, and safety performance. Multiple regression results found 44% of the variation in safety performance explained by job autonomy, length of employment, and perceptions of organizational policy. CONCLUSION: Job autonomy and perceptions of organizational policy were positively related to safety performance. Hospital executives and nurse managers should work to enhance job autonomy and positive perceptions of organizational policy, to contribute to improving patient safety.

[Safety in shipping: the role of the human factor.] / Sicurezza nella navigazione: il ruolo del fattore umano.

OBJECTIVES: The main aim of this paper is to examine the role of human factors in the safety of ship transport (shipping). METHODS: Particularly, we analyzed the personal, psychosocial and organizational factor that intervene in this context and the consequences on the safety performance and workers' well-being. RESULTS: In this review, some shipping accidents and their causes are presented and a particular attention will be paid to human error, fatigue and stress, non-technical skills and perception of safety. CONCLUSIONS: In the final part of the paper the safety performance and its antecedents in the context of shipping will be extensively examined.

Use of portable ladders - field observations and self-reported safety performance in the cable TV industry.

Portable ladders incidents remain a major cause of falls from heights. This study reported field observations of environments, work conditions and safety behaviour involving portable ladders and their correlations with self-reported safety performance. Seventy-five professional installers of a company in the cable and other pay TV industry were observed for 320 ladder usages at their worksites. The participants also filled out a questionnaire to measure self-reported safety performance. Proper setup on slippery surfaces, correct method for ladder inclination setup and ladder secured at the bottom had the lowest compliance with best practices and training guidelines. The observation compliance score was found to have significant correlation with straight ladder inclined angle (Pearson's r = 0.23, p < 0.0002) and employees' self-reported safety participation (r = 0.29, p < 0.01). The results provide a broad perspective on employees' safety compliance and identify areas for improving safety behaviours. Practitioner Summary: A checklist was used while observing professional installers of a cable company for portable ladder usage at their worksites. Items that had the lowest compliance with best practices and training guidelines were identified. The results provide a broad perspective on employees' safety compliance and identify areas for improving safety behaviours.

Defining and Measuring Safety Climate: A Review of the Construction Industry Literature.

Safety climate measurements can be used to proactively assess an organization's effectiveness in identifying and remediating work-related hazards, thereby reducing or preventing work-related ill health and injury. This review article focuses on construction-specific articles that developed and/or measured safety climate, assessed safety climate's relationship with other safety and health performance indicators, and/or used safety climate measures to evaluate interventions targeting one or more indicators of safety climate. Fifty-six articles met our inclusion criteria, 80% of which were published after 2008. Our findings demonstrate that researchers commonly defined safety climate as perception based, but the object of those perceptions varies widely. Within the wide range of indicators used to measure safety climate, safety policies, procedures, and practices were the most common, followed by general management commitment to safety. The most frequently used indicators should and do reflect that the prevention of work-related ill health and injury depends on both organizational and employee actions. Safety climate scores were commonly compared between groups (e.g. management and workers, different trades), and often correlated with subjective measures of safety behavior rather than measures of ill health or objective safety and health outcomes. Despite the observed limitations of current research, safety climate has been promised as a useful feature of research and practice activities to prevent work-related ill health and injury. Safety climate survey data can reveal gaps between management and employee perceptions, or between espoused and enacted policies, and trigger communication and action to narrow those gaps. The validation of safety climate with safety and health performance data offers the potential for using safety climate measures as a leading indicator of performance. We discuss these findings in relation to the related concept of safety culture and offer suggestions for future research and practice including (i) deriving a common definition of safety climate, (ii) developing and testing construction-specific indicators of safety climate, and (iii) focusing on construction-specific issues such as the transient workforce, subcontracting, work organization, and induction/acculturation processes.