Effects of time-gap settings of adaptive cruise control (ACC) on driving performance and subjective acceptance in a bus driving simulator

A study was conducted to investigate the effects of time-gap settings and contents of secondary tasks on a fix-based bus driving simulator on drivers’ performance while reclaiming control from ACC in a car-following scenario of emergency brake by the lead vehicle. Thirty professional bus drivers drove on the simulator with the scenario of highway traffic flow under 12 random time-gap settings: from 0.64 s to 2.40 s with the interval of 0.16 s. As for the effects of secondary tasks, subjects were evenly divided into three conditions: no secondary task interference, simple secondary task, and complex task. The results demonstrated that different safety demarcations of time-gaps on subjective acceptance and driving performance can be found out. The integrated demarcations separated time-gaps into divisions that represented different levels of danger. It revealed that the safer time-gaps for different situations were: longer than 1.60 s for none-secondary task distraction and longer than 2.08 s for being continuously distracted by secondary tasks. The demand for simple tasks is relatively high, so a larger time-gap is needed for the driver to remain safe. This research has implications for the time-gap selection of ACC and effects of secondary task distraction on buses. A next logical step will focus on determining time-gaps for lead vehicles on curves or slopes, when multiple vehicles are present ahead, and modeling driver behavior and performance with ACC for cars, buses, and other types of vehicles.     

Perspectives on safety: The impact of group membership,work factors and trust on safety performance in UK and Norwegian drilling company employees

This study is anchored in a contractor company providing well services for platform drilling on the Norwegian (NCS) and the UK Continental Shelves (UKCS). The research project has as its point of departure the potential influences of group level characteristics, structural work factors, trust, and safety behaviour on safety performance. Do perceptions and performance differ across Shelves? Are “nomadic” groups or employees that have more unpredictable shift rotations more exposed to accidents than others? Is high trust and sound safety behaviour enhancing good safety performance? The results are based on questionnaire data from two samples of personnel distributed across three installations on the UKCS and nine on the NCS with a response rate of 67%: N = 170 (UKCS) and N = 621 (NCS). In addition, two focus group interviews were held in each country, with 15 participants in each. The results show that our model makes sense. Shelf shows a significant influence on safety performance in all but the final stage in our five-step logistic regression model, indicating that the effect may be mediated by safety compliance and safety participation. Installations and different work teams have different exposure and structural work factors matter significantly. Somewhat counter-intuitively, employees who have a “nomadic” status and who hold the least regular shift rotations appear to have a lower risk of being involved in incidents. High trust in workmates buffers against incident involvement and the same applies for high safety compliance. The results, challenges and implications for research and safety practitioners are discussed.     

Implications of job insecurity perceptions and job insecurity responses for psychological well-being,turnover intentions and reported risk behavior

This study aimed to test whether cognitively appraised level of job insecurity (job insecurity perceptions) and evaluative responses to a perceived level of job insecurity (job insecurity dissatisfaction and job insecurity behaviors) could relate differently to employee mental well-being, turnover intentions and on-the-job risk behavior. The significance of demographic characteristics (gender and age) as well as the implications of attitudinal variables (job satisfaction, job motivation and organizational commitment) and for the dependent variables was taken into account. Based on data from a self-completion questionnaire survey carried out among a representative sample of the Norwegian adult population (N = 260) results indicated that only job insecurity behaviors were indirectly related to turnover intentions and risk behavior via their impact on psychological well-being. The relative importance of the job insecurity dimensions for the dependent variables are discussed, as well as theoretical and practical implications.     

The development of an intervention to improve the safety of community care nurses while driving and a qualitative investigation of its preliminary effects

This paper details the development of, and perceived role and effectiveness of an innovative intervention designed to ultimately improve the safety of a group of community care (CC) nurses while driving. Recruiting participants from an Australian CC nursing car fleet, qualitative responses from a series of open-ended questions were obtained from drivers (n = 36), supervisors (n = 22), and managers (n = 6). The findings supported the effectiveness of the intervention in reducing self-reported speeding and promoting greater insight into one’s behaviour on the road. This research has important practical implications in that it highlights the value of developing an intervention based on a sound theoretical framework and which is aligned with the needs and beliefs of personnel within a particular organisation.     

Cross-cultural comparisons of traffic safety,risk perception,attitudes and behaviour

The core aim of the present study is to examine cultural differences in risk perception and attitudes towards traffic safety and risk, taking behaviour in the Norwegian and the Ghanaian public. An additional aim is to discuss the applicability of various traffic measures, suited for low and middle income countries in Africa.Sample: The results of the present study are based on two self-completion questionnaire surveys carried out in February and March 2006. The first was a representative sample of the Norwegian public above 18 years of age (N = 247). The second was a stratified sample of Ghanaian respondents (N = 299). In Ghana the data was collected in Accra and Cape Coast.The results showed that there is potential for further improvement of safety attitudes and risk behaviour among Ghanaians as well as Norwegians. There were also differences in the respondents’ evaluation of attitudes, risk perception and behaviour. Perceived risk and attitudes also significantly predicted risk behaviour and accidents/collisions. The implications of these results for traffic safety will be discussed.     

Evaluation of an in-vehicle monitoring system (IVMS) to reduce risky driving behaviors in commercial drivers: Comparison of in-cab warning lights and supervisory coaching with videos of driving behavior

ProblemRoadway incidents are the leading cause of work-related death in the United States.MethodsThe objective of this research was to evaluate whether two types of feedback from a commercially available in-vehicle monitoring system (IVMS) would reduce the incidence of risky driving behaviors in drivers from two companies. IVMS were installed in 315 vehicles representing the industries of local truck transportation and oil and gas support operations, and data were collected over an approximate two-year period in intervention and control groups. In one period, intervention group drivers were given feedback from in-cab warning lights from an IVMS that indicated occurrence of harsh vehicle maneuvers. In another period, intervention group drivers viewed video recordings of their risky driving behaviors with supervisors, and were coached by supervisors on safe driving practices.ResultsRisky driving behaviors declined significantly more during the period with coaching plus instant feedback with lights in comparison to the period with lights-only feedback (ORadj = 0.61 95% CI 0.43–0.86; Holm-adjusted p = 0.035) and the control group (ORadj = 0.52 95% CI 0.33–0.82; Holm-adjusted p = 0.032). Lights-only feedback was not found to be significantly different than the control group's decline from baseline (ORadj = 0.86 95% CI 0.51–1.43; Holm-adjusted p > 0.05).ConclusionsThe largest decline in the rate of risky driving behaviors occurred when feedback included both supervisory coaching and lights.Practical applicationsSupervisory coaching is an effective form of feedback to improve driving habits in the workplace. The potential advantages and limitations of this IVMS-based intervention program are discussed.     

Antecedents of intention to help mitigate wildfire: Implications for campaigns promoting wildfire mitigation to the general public in the wildland–urban interface

The current investigation sought to examine the association between knowledge of the causes of wildfire in the wildland–urban interface (WUI) and intentions on the part of members of the public to help mitigate wildfire. In doing so, antecedents from the theory of planned behavior were employed to enhance our understanding of the relationships among wildfire knowledge, attitudes, subjective norms, perceived behavioral control, and intention to help mitigate wildfire in the WUI. Participants (N = 408) living in the WUI in Appalachian Ohio were sampled as a means of conducting formative research prior to developing messages promoting wildfire mitigation. Our results reveal that, among the variables in the theory of planned behavior, the only paths that consistently explain individual’s intention to help mitigate wildland fire in the WUI in protecting both homes and the environment are associations between knowledge about wildfire and perceived behavioral control and between perceived behavioral control and intention. Our findings are discussed with a focus on message design for wildland fire mitigation professionals and a focus on implications for the theory of planned behaviors for academics with interests in wildland fire and other environmental issues.     

The use and risk of portable electronic devices while cycling among different age groups

Introduction: In the Netherlands, a survey was set up to monitor the extent of the use of portable, electronic devices while cycling amongst different age groups of cyclists and to estimate the possible consequences for safety. Method: The main research questions concerned age differences in the self-reported use of electronic devices while cycling, self-reported crash involvement and risk, and self-reported compensatory behaviour. Teen cyclists (12–17 years) and young adult cyclists (18–34 years) were more frequent users, and also more indiscriminate users of portable devices while cycling than middle-aged and older adult cyclists (35–49 years; 50 + years). Results: After statistical correction for influences on crash risk of urbanization level, weekly time spent cycling, and cycling in more demanding traffic situations, the odds of being involved in a bicycle crash were estimated to be higher for teen cyclists and young adult cyclists who used electronic devices on every trip compared to same age groups cyclists who never used these devices. For middle-aged and older adult cyclists, the use of portable electronic devices was not a significant predictor of bicycle crashes, but frequency of cycling in demanding traffic situations was. Possible implications for education or legal measures are discussed. Impact on Industry: Results may inform researchers, policy makers, and cyclists themselves. Educational campaigns may use risk information to warn young cyclists about risk of device use while cycling.     

Access to trauma centers for road crashes in the United States

Introduction: Existing research indicates that around 90% of all U.S. residents have access to at least one level I or II trauma center within 60 min. However, a limitation of these estimates lies in that they are based on where people live and not where people are injured, which may overestimate the access to trauma centers for seriously injured patients in fatal crashes. Method: In this study, the Fatality Analysis Reporting System (FARS) data between 2013 and 2014 were collected and analyzed to quantify the access of injured patients to trauma centers for fatal crashes across states. Two types of distance, linear distance and route distance, were calculated using ArcGIS. The estimated transport time to the nearest level I/II trauma center was also calculated and compared to the recorded on-scene and transport time. Results and Conclusions: The Northeast region had the nearest average linear and route distance between fatal crash and trauma center (25.3 km and 31.7 km, respectively), followed by the Midwest (44.4 km and 54.1 km), the South (47.3 km and 57.0 km), and the West (50.9 km and 67.5 km). The comparison between the estimated and actual transport time revealed that the different states adopted different trauma triage protocols, resulting in different utilization rates of the level I/II trauma center among states. A linear regression analysis demonstrated that the longer the average route distance, the less the seriously injured patients in fatal crashes were taken to level I/II trauma center directly. Practical applications: These findings may help to identify the access to trauma centers for road crashes and the variation of delivery ratio to trauma center among the states, therefore a better utilization of trauma centers for road crashes can be achieved for the emergency medical services (EMS) systems.     

Healthcare utilization and costs among older adult female drivers and former drivers

PurposeThis study compared the healthcare utilization and costs for specific types of medical services among older adult women who currently drive and those who no longer drive.MethodsThis study included 347 women aged 65 or older who were either former (had stopped driving) or current drivers, randomly sampled from a large U.S. health plan to participate in a telephone survey, and who had automated health records with healthcare utilization and cost data. Bivariate analyses and generalized linear modeling were used to examine associations between driving status and healthcare utilization and costs.ResultsAdjusting for age, income, and marital status, former drivers were more likely than current drivers to use mental health care services (RR = 3.37; 95% CI: 1.03, 10.98). Former drivers also tended to use more inpatient (RR = 1.85; 95% CI: 0.88, 3.87) and emergency services (RR = 1.89; 95% CI: 0.96, 3.70), but results did not reach statistical significance. Total annual healthcare costs in 2005 were almost twice as high for former drivers compared with current drivers ($13,046 vs. $7,054; mean difference = $5,992; 95% CI: -$360, $12,344), although this relationship was not statistically significant (CR = 1.61; 95% CI: 0.88, 2.96).Impact on IndustryFormer drivers were more than three times as likely as current drivers to use mental health services, and tended to use more emergency and inpatient services. Further research on factors that potentially mediate the relationship between driving status and health service use is warranted.     

Removal of toluene vapour from air stream using a biofilter packed with polyurethane foam

Biodegradation of toluene vapour was investigated for 168 days in a polyurethane packed biofilter inoculated with a mixed microbial population. Biofilter consisted of five square cross-section modular units each of size 0.16 m × 0.16 m × 0.20 m and filled with the polyurethane foam cubes up to a height of 0.15 m. Inlet concentration of toluene was varied from 0.04 to 2.5 g m^?3 and the volumetric flow rate of toluene loaded air from 0.06 to 0.90 m³ h^?1.Depending upon initial loading rates, removal efficiency ranging from 68.2 to 99.9% and elimination capacity ranging from 10.85 to 90.48 g h^?1 m^?3 were observed during steady state operations. More than 90% removal efficiency was observed up to an inlet loading rate of 76.3 g h^?1 m^?3. High carbon recovery (>90%) indicated effective biodegradation in the bed. Low variation of pH (7.2–8.8) and pressure drop (45.8–76.3 Pa) was observed. The stability of the biomass was evident from the fast response of the biofilter to shutdown and restartup.     

An efficient framework of emergency response to facilitate disaster recovery for fire-damaged medical equipment – Case study at a large medical centre after a fire

The major role of disaster recovery management is to rapidly restore the chaotic condition to normal, which includes mitigation, preparedness, response, and recovery. To reduce secondary damage and loss, the recovery process must be facilitated. Information technologies (including network, web-based, computer, and related software tools) speed up the work process to rapidly deliver disaster information to the related department. In this paper, we share an experience that used a framework of emergency response, including a simple pre-operating process and a web-based information system, to effectively manage and control damaged medical equipment after a fire accident in a hospital operating room. This web-based information system was built in only 2 weeks and was used to manage a large amount of medical equipment affected by the fire. Since then, it effectively prevented the interruption of clinical work at 22 clinical units by supporting the reconstruction activities.     

Nursing student evaluation of NIOSH workplace violence prevention for nurses online course

Introduction: As primary targets of workplace violence in health care settings, nurses may suffer negative physical and psychological consequences. NIOSH created an online course to educate nurses about violence prevention techniques. Method: A mixed-methods approach assessed workplace violence awareness and knowledge among nursing students. A pre/post/post-test survey and focus group discussions evaluated participant awareness and knowledge, assessed course design, and solicited recommendations for increasing participation and strategies for improving message retention. Results: The mean awareness scores differed significantly between pre-course and both post-course time points (Wilk's λ = 0.319, F(2, 46) = 49.01, p < 0.001). Post hoc tests using the Bonferroni correction revealed that course participation increased awareness of workplace violence from pre-course scores (M = 0.75, SD = 0.438) to immediate post-course (M = 2.13, SD = 0.789) and four-week post-course (M = 1.96, SD = 0.771) scores on a 3-item measure. Similarly, mean knowledge scores increased between pre-course and both post-course time points (Wilk's λ = 0.495, F(1.57, 73.66) = 37.26, p < 0.001). Post hoc tests using the Bonferroni correction revealed that course participation increased knowledge of workplace violence from pre-course scores (M = 6.65, SD = 1.45) to immediate post-course (M = 8.56, SD = 1.32) and four-week post-course (M = 8.19, SD = 1.42) scores on a 10-item measure. Qualitative data from the focus groups reinforced the quantitative findings. Participants citing benefits from the content strongly recommended including the course in nursing curriculums. Incorporating the course early in the nursing educational experience will better prepare students to deal with workplace violence when they enter health care professions. Conclusions: The results indicate that NIOSH and its partners created an effective online workplace violence awareness and prevention course. Practical applications: Nursing students and professionals can be effectively educated about workplace violence using an online format.     

Overall and local movement speeds during fire drill evacuations in buildings up to 31 stories

The time that it takes an occupant population to reach safety when descending a stairwell during building evacuations is typically described by measurable engineering variables such as stairwell geometry, speed, density, and pre-evacuation delay. In turn, engineering models of building evacuation use these variables to predict the performance of egress systems for building design, emergency planning, or event reconstruction. As part of a program to better understand occupant movement and behavior during building emergencies, the Engineering Laboratory at the National Institute of Standards and Technology (NIST) has been collecting stairwell movement data during fire drill evacuations of office buildings. These data collections are intended to provide a better understanding of this principal building egress feature and develop a technical foundation for future codes and standards requirements. To date, NIST has collected fire drill evacuation data in eight office building occupancies ranging from 6 to 62 stories in height that have included a range of stairwell widths and occupant densities.While average movement speeds in the current study of 0.48 m/s ± 0.16 m/s are observed to be quite similar to the range of literature values, local movement speeds as occupants traverse down the stairwell are seen to vary widely within a given stairwell, ranging from 0.056 m/s to 1.7 m/s. These data should provide confirmation of the adequacy of existing literature values typically used for occupant movement speeds or provide updated values for future analyses.     

The relationship between patient safety climate and occupational safety climate in healthcare – A multi-level investigation

IntroductionPatient safety climate/culture is attracting increasing research interest, but there is little research on its relation with organizational climates regarding other target domains.The aim of this study was to investigate the relationship between patient safety climate and occupational safety climate in healthcare.MethodThe climates were assessed using two questionnaires: Hospital Survey on Patient Safety Culture and Nordic Occupational Safety Climate Questionnaire. The final sample consisted of 1154 nurses, 886 assistant nurses, and 324 physicians, organized in 150 work units, within hospitals (117 units), primary healthcare (5 units) and elderly care (28 units) in western Sweden, which represented 56% of the original sample contacted.ResultsWithin each type of safety climate, two global dimensions were confirmed in a higher order factor analysis; one with an external focus relative the own unit, and one with an internal focus. Two methods were used to estimate the covariation between the global climate dimensions, in order to minimize the influence of bias from common method variance. First multilevel analysis was used for partitioning variances and covariances in a within unit part (individual level) and a between unit part (unit level). Second, a split sample technique was used to calculate unit level correlations based on aggregated observations from different respondents. Both methods showed associations similar in strength between the patient safety climate and the occupational safety climate domains.ConclusionsThe results indicated that patient safety climate and occupational safety climate are strongly positively related at the unit level, and that the same organizational processes may be important for the development of both types of organizational climate.Practical applicationsSafety improvement interventions should not be separated in different organizational processes, but be planned so that both patient safety and staff safety are considered concomitantly.     

Risk factors associated with bus accident severity in the United States: A generalized ordered logit model

IntroductionRecent years have witnessed a growing interest in improving bus safety operations worldwide. While in the United States buses are considered relatively safe, the number of bus accidents is far from being negligible, triggering the introduction of the Motor-coach Enhanced Safety Act of 2011.MethodThe current study investigates the underlying risk factors of bus accident severity in the United States by estimating a generalized ordered logit model. Data for the analysis are retrieved from the General Estimates System (GES) database for the years 2005–2009.ResultsResults show that accident severity increases: (i) for young bus drivers under the age of 25; (ii) for drivers beyond the age of 55, and most prominently for drivers over 65 years old; (iii) for female drivers; (iv) for very high (over 65 mph) and very low (under 20 mph) speed limits; (v) at intersections; (vi) because of inattentive and risky driving.     

Comparisons of TGA and DSC approaches to evaluate nitrocellulose thermal degradation energy and stabilizer efficiencies

This study investigated the thermal degradation energy (activation energy, E_a) for nitrocellulose (NC) with low nitrogen content of 11.71 mass%, so-called NC3, by using two different kinds of thermal analysis instruments: thermogravimetric analyzer (TGA) and differential scanning calorimetry (DSC). A comparison of E_a for various nitrogen content NC samples at two scanning rates (5 and 10 °C min^?1) tested by TGA and DSC is also discussed in this paper. Meanwhile, our aim was to analyze the anti-degradation of E_a for NC with high nitrogen content, as so-called NC1. Thermal stability for NC1 with diphenylamine (DPA) was tested via DSC with 10 DPA concentrations in weights of 0, 0.25, 0.50, 0.75, 1.0, 1.25, 1.50, 1.75, 2.0, and 3.0 mass%. Experimental results indicated that E_a of NC3s was 319.91 kJ mol^?1. Moreover, that while dosing DPA into NC1 the best recipe could be employed to avoid any violent NC1 runaway and also can be used to distinguish the differences of thermal decomposition E_a between NC with different nitrogen contents. This study established a fast and efficient procedure for thermal decomposition properties of NC, and could be applied as an intrinsically safer design during relevant operations.     

Biofiltration of gas-phase hexane and toluene mixture under intermittent loading conditions

This paper reports the performance of a compost biofilter subjected to periodic intermittent loads of gas-phase hexane and toluene. The biofilter was operated for 10 h per day, at different empty bed residence times (4, 2 and 1.3 min), and at different inlet concentrations of hexane and toluene, varying between 2 and 3.8 g m^?3, respectively. Steady-state removal efficiency profiles, reaching more than 90% for both the pollutants, was observed after 44 days of operation. Periodic operation of the compost biofilter was characterized by an adsorption step, followed by biological conversion of the pollutants by the microorganisms inherent to the compost. After resuming daily biofilter operation, the required times for biochemical reaction to dominate the initial adsorption step was observed to be 2.5 and 1 h, respectively, for toluene and hexane. The maximum elimination capacity due to the biological step was found to be 61.6 g m^?3 h^?1. The results from this study showed the effectiveness of the biofilter to handle mixtures of gas-phase pollutants, subjected to regular intermittent operations, thus proving their worthiness for industrial use.     

Sensitivity analysis and optimization for gasoline vapor condensation recovery

Volatile organic compounds (VOCs) are easily evaporated and discharged from everywhere into the atmosphere, especially in various operations of gasoline. The emission of VOCs is always a significant environmental problem, and the control of VOCs pollution has been a hot topic in the field of air purification. In this paper, the condensation separation method for gasoline vapor recovery was investigated and four gasoline vapors of S1–S4 were selected for the sensitivity analysis and optimization of the condensation process, using the Model Analysis Tools from Aspen Plus. Generally, to control VOCs pollution efficiently, both the vapor recovery efficiency and the outlet vapor concentration of the condensation recovery system should be simultaneously considered. Then an optimized three-stage condensation process was proposed, whose condensation temperatures were optimized and designed at 1 °C, −40 °C and −110 °C, respectively. Further, based on the comprehensive consideration of both meeting the more strict VOCs emission standard and ensuring the condensation recovery system work stably and economically, it was recommended that the maximum total vapor recovery efficiencies for S1–S4 should be 99.73%, 99.79%, 99.82% and 99.19%, and the minimum outlet vapor concentrations be 2.87 g/m³, 2.75 g/m³, 3.04 g/m³ and 16.98 g/m³, respectively. Accordingly, the condensation temperature of the copious cooling stage should be set at −130 °C. Moreover, the total cooling duties for the single-stage and three-stage condensation processes were investigated and compared when the condensation temperature of the recovery system ranged from 20 °C to −110 °C. The total cooling duties of the three-stage condensation process for S1–S4 would be saved by 12.23%, 15.68%, 13.96% and 15.65%, respectively. Finally, a three-stage condensation system was developed for the industrial gasoline vapor recovery, which has performed well since its installation.