Safety, Volume 6, Issue 3 (September 2020) – 10 articles

This paper examines the transferability of the Safety Performance Function (SPF) of the Highway Safety Manual (HSM) and other 10 international SPFs for total crashes on rural multi-lane divided roads in Egypt. Four segmentation approaches are assessed in the transferability of the international SPFs, namely: (1) one-kilometer segments (S1); (2) homogenous sections (S2); (3) variable segments with respect to the presence of curvatures (S3); and (4) variable segments with respect to the presence of both curvatures and U-turns (S4). The Mean Absolute Deviation (MAD), Mean Prediction Bias (MPB), Mean Absolute Percentage Error (MAPE), Pearson χ² statistic, and Z-score parameters are used to evaluate the performance of the transferred models. The overdispersion parameter (k) for each transferred model and each segmentation approach is recalibrated using the local data by the maximum likelihood method. Before estimating the transferability calibration factor (Cr), three methods were used to adjust the local crash prediction of the transferred models, namely: (1) the HSM default crash modification factors (CMFs); (2) local CMFs; and (3) recalibrating the constant term of the transferred model. The latter method is found to outperform the first two methods. Besides, the results show that the segmentation method would affect the performance of the transferability process. Moreover, the Italian SPFs based on the S1 segmentation method outperforms the HSM and all of the investigated international SPFs for transferring their models to the Egyptian rural roads. Full article

Various safety-related standards associated with the machinery design phase, such as ISO 14119:2013, emphasize the appropriate design and selection of protective devices to prevent bypassing. Despite such standards, bypassing safeguards is a common issue at the machinery use phase. ISO 12100:2010 indicates, “experience has shown that even well-designed safeguarding can fail or be violated”. This unsafe practice can cause serious injuries or fatalities. This paper presents an improved version of a bypassing-related assessment tool initially inspired by ISO 14119. The improvement results from testing its performance through industrial case studies to explore how the tool works in reality. Five occupational health and safety (OHS) practitioners apply this tool in four plants in Quebec to 18 machines and 37 activities. Afterwards, the OHS practitioners provide feedback using a questionnaire. The findings reveal that the tool is appropriate for the machine usage phase to prevent bypassing with an overall 82% satisfaction score. The probability levels of bypassing given by the tool enable a safety improvement prioritization method for the machines and safeguards. The tool was improved, redefining some incentives to bypass and its layout. The findings explain how practitioners could influence decision-making to minimize incentives to bypass and the probability of bypassing to prevent accidents. Full article

Efforts to disseminate heat-related illness (HRI) prevention practices among Latino farmworkers represent a critical occupational safety strategy in Florida. Targeted initiatives, however, require understanding the workplace dynamics that guide agricultural safety behaviors. This article reports focus group data collected in 2018 from citrus harvesters in central Florida and provides an in-depth perspective on the workplace culture that shapes their implementation of heat safety measures. Results indicate that citrus harvesters regularly suffered HRI symptoms yet rarely reported or sought treatment for their injuries. In some cases, the risks of developing HRI were accepted as a facet of agricultural work and harvesters blamed themselves for their illnesses. Implementation of safety practices hinged less on knowledge than on the availability of water and rest breaks and the quality of employer-employee relations and exchanges. Thus, trust was a determinant of workers’ attitudes toward management that contributed to a harvesting operation’s safety climate. Results highlight the difficulties of putting into practice measures that are not rewarded by the workplace culture and suggest that the extent to which intervention strategies promote not only individual safety behaviors but organizational accountability may predict their effectiveness. Full article

Subcontractors have always been linked to higher risk by the industry and academia. However, not much work exists in establishing the reasons behind this relationship. Much of the existing work, either categorise subcontractors under a theoretical label of work to apply the drawbacks of the label to them, or directly enter problem-solving mode. This study focusses on taking the perspective of subcontractors and explores ways in which this viewpoint interacts with safety systems and processes. This study applies a case study methodology to this problem. It examines a total of six cases reflecting six closed single subcontractor fatality accident investigation reports from the year 2004 to 2014 obtained from the Department of Natural Resources and Mines (DNRM) Queensland. These cases are then thematically analysed by employing subcontractor theory to identify themes to categorise the links between higher risk and subcontractors. The themes identified match two pre-existing categories (Institutional safety mechanisms do not cope with variability introduced by subcontractors; expertise in work does not translate to expertise in safety) and two new categories (communication does not flow to the subcontractor from the layers above them; safety work is viewed differently by subcontractor staff when compared to principal contractor’s/operators’) of subcontractor risk. This study aims to serve as a starting point for further research in understanding the subcontractor safety situation by putting things into the subcontractor’s perspective. Full article

Fully electric ships have been widely developed, investigated and evaluated by the maritime industry as a potential solution to respond to the emissions control required according to the International Maritime Organization (IMO). This study aims at presenting a novel approach to evaluate the safety level of a battery-powered high speed catamaran. Following the Formal Safety Assessment procedure, the risk assessment of the considered ship was conducted leading to the identification of the involved hazards along with the estimation of their frequency and consequences thus allowing for the identification of the most severe hazards. Fault tree analysis is carried out for and the identified top events followed by an event tree analysis to estimate the risk and safety level of the vessel. Furthermore, a cost-benefit assessment is conducted to evaluate the financial impact of selected risk control options. The derived results indicate that the application of battery power systems for high speed ferries exhibits low and acceptable accident frequencies. It is also supported the current regulation to carry out mandatory risk assessment for battery-powered ships. Full article

The goal of section speed control is to increase speed limit compliance in the monitored road sections, decrease speed variance and improve traffic safety. General experience with section speed control on motorways is positive, with significant improvements in both speed and safety performance. The presented study focused on a unique application of section speed control in motorway work zones in the Czech Republic. Effectiveness was monitored (in terms of average speed, speeding and accident rates) in three sections and four time periods (normal operation, work zone, work zone with section speed control, normal operation), which allowed discerning individual effects of work zone and section speed control. In addition, a novel data source—floating car data—was used. Work zones were found to increase accident rates compared to normal operation and decrease with the introduction of section speed control. The effects on average speed, speed variance and speeding were positive, although smaller compared to the studies conducted in non-work zone conditions. Full article

Interest in resilience engineering for improving organisational safety continues to grow among safety scholars and practitioners, but little attention has focused on a unifying definition, characteristics, and instruments for quantitative measurements. This is a significant gap which can impede efforts at benchmarking and evaluating resilience engineering for organisational safety. This integrative review was undertaken to address this research-practice gap in order to inform a theoretical framework. A five steep integrative literature review process was used to retrieve and critically evaluate peer-reviewed quantitative research articles published or in press from 2003 to November 2019. From the 3884 studies identified, screened, and selected, 17 met the final inclusion criteria. In total, 15 specific instruments were identified, but only four were grounded on a theoretical framework or model—the most common instrument used for included structured surveys. A minimum of three and a maximum of 13 characteristics were measured; however, it is not clear what type of variables they represented. The six most common characteristics included top management commitment, just culture, learning culture, awareness, preparedness, and flexibility. An integrative model of how these can inform a Resilience Climate Questionnaire (RCQ) survey is presented. Full article

To evaluate the risk of a pipe in the water supply network of Beijing, we used the accident records of the gridding urban management (GUM) system. In addition, road and building information derived from a three-dimensional (3D) electronic map was also employed. A machine learning algorithm, the decision tree, was employed to train and evaluate the dataset. The results show that the contributions of the surrounding buildings and roads are neglectable, except for super-high-rise buildings, which have limited contributions. This finding is consistent with the results of other studies. The decision tree identifies dominant features and isolates the risk contribution of such features. The output tree structure indicated that the time since the last accident is a dominant factor, to which super-high-rise buildings contribute slightly. A cut-off value of 0.019 was chosen to predict high-risk regions. Approximately 0.4% of the data were predicted to be high risk, and the corresponding gain in risk rate was approximately 19.2. This model may be used in cities where detailed profiles of water supply pipes and maintenance records are not available or are expensive to achieve. Full article

Decrements to postural control manifest as an increase in muscle activity, indicating continuous attempts to maintain body equilibrium and postural stability. Extrinsic factors such as footwear, and intrinsic factors such as muscle fatigue, can affect postural stability. The purpose of this study was to analyze the impact of two types of military footwear and a military-type load-carrying task on lower extremity muscle activity during various postural stability tasks. Sixteen males’ (age: 26.63 ± 3.93 years; mass: 87 ± 12.4 kg; height: 178.04 ± 6.2 cm) muscle activity from knee flexors, extensors, ankle dorsiflexors, and plantar flexors were measured using electromyography in standard (STD) and minimalist (MIN) military footwear, before (PRE) and after (POST) a simulated workload during sensory organization and motor control tests on the Neurocom EquitestTM. Mean muscle activity was analyzed using 2 (footwear) × 2 (time) repeated measures ANOVA with an alpha level of 0.05. Results revealed a requirement of significantly greater muscle activity in POST and STD. MIN demonstrated lesser balance decrements POST workload, which could be attributed to its design characteristics. Results will help in suggesting footwear design characteristics to minimize muscular exertion while eliciting better postural control, and to prevent postural instability due to overexertion in military personnel. Full article

A new concept in the interior design of autonomous vehicles is rotatable or swivelling seats that allow people sitting in the front row to rotate their seats and face backwards. In the current study, we used a take-over request task conducted in a fixed-based driving simulator to compare two conditions, driver front-facing and rear-facing. Thirty-six adult drivers participated in the experiment using a within-subject design with take-over time budget varied. Take-over reaction time, remaining action time, crash, situation awareness and trust in automation were measured. Repeated measures ANOVA and Generalized Linear Mixed Model were conducted to analyze the results. The results showed that the rear-facing configuration led to longer take-over reaction time (on average 1.56 s longer than front-facing, p < 0.001), but it caused drivers to intervene faster after they turned back their seat in comparison to the traditional front-facing configuration. Situation awareness in both front-facing and rear-facing autonomous driving conditions were significantly lower (p < 0.001) than the manual driving condition, but there was no significant difference between the two autonomous driving conditions (p = 1.000). There was no significant difference of automation trust between front-facing and rear-facing conditions (p = 0.166). The current study showed that in a fixed-based simulator representing a conditionally autonomous car, when using the rear-facing driver seat configuration (where participants rotated the seat by themselves), participants had longer take-over reaction time overall due to physical turning, but they intervened faster after they turned back their seat for take-over response in comparison to the traditional front-facing seat configuration. This behavioral change might be at the cost of reduced take-over response quality. Crash rate was not significantly different in the current laboratory study (overall the average rate of crash was 11%). A limitation of the current study is that the driving simulator does not support other measures of take-over request (TOR) quality such as minimal time to collision and maximum magnitude of acceleration. Based on the current study, future studies are needed to further examine the effect of rotatable seat configurations with more detailed analysis of both TOR speed and quality measures as well as in real world driving conditions for better understanding of their safety implications. Full article