Using alcohol intoxication goggles (Fatal Vision® goggles) to detect alcohol related impairment in simulated driving

Objective: Fatal vision goggles (FVGs) are image-distorting equipment used within driver education programs to simulate alcohol-related impairment. However, there is no empirical evidence comparing the behavioral effects associated with wearing FVGs to alcohol intoxication. The purpose of this study was to determine the validity of FVGs in producing alcohol-related impairment in simulated driving.

Methods: Twenty-two healthy males (age: 23 ± 3 years, mean ± SD) participated in a placebo-controlled crossover design study involving 4 experimental trials. In each trial, participants completed a baseline level simulated driving task followed by an experimental driving task, involving one of 4 treatments: (1) a dose of alcohol designed to elicit 0.080% breath alcohol concentration (BrAC; AB), (2) an alcohol placebo beverage (PB), (3) FVG (estimated % blood alcohol concentration [BAC] 0.070–0.100+), and (4) placebo goggles (PGs). The driving tasks included 3 separate scenarios lasting ～5 min each; these were a simple driving scenario, a complex driving scenario, and a hazard perception driving scenario. Selected lateral control parameters (standard deviation of lane position [SDLP]; total number of lane crossings [LCs]) and longitudinal control parameters (average speed; standard deviation of speed [SDSP]; distance headway; minimum distance headway) were monitored during the simple and complex driving scenarios. Latency to 2 different stimuli (choice reaction time [CRT]) was tested in the hazard perception driving scenario. Subjective ratings of mood and attitudes toward driving were also provided during each of the trials.

Results: Neither placebo treatment influenced simulated driving performance. Mean BrAC was 0.060 ± 0.010% at the time of driving on the AB trial. Lateral control: In the simple driving scenario, SDLP and LC were not affected under any of the experimental treatments. However, in the complex driving scenario, significantly greater SDLP was observed on both the FVG and AB trials compared to their respective baseline drives. LC increased significantly from baseline on the AB trial only. Longitudinal control: Speed was not affected by any of the experimental treatments; however, SDSP increased significantly from baseline on the FVG trial. A significant reduction in distance headway and minimum distance headway was detected on the FVG trial compared to baseline. Hazard perception: Neither AB nor FVG trials were influential on CRT. Subjective mood ratings were significantly altered on the AB and FVG trials compared to baseline and placebo conditions. Participants reported reduced willingness and ability to drive under the active treatments (AB and FVG) than the placebo treatments (PB and PG).

Conclusions: FVGs may have some utility in replicating alcohol-related impairment on specific driving performance measurements. Hence, the equipment may offer an alternative approach to researching the impact of alcohol intoxication on simulated driving performance among populations where the provision of alcohol would otherwise be unethical (e.g., prelicensed drivers).     

Validity of police-reported alcohol involvement in fatal motor carrier crashes in the United States between 1982 and 2005

Objective

To examine the validity of police-reported alcohol data for drivers involved in fatal motor carrier crashes.

Material and Methods

We determined the availability of blood alcohol concentration (BAC) and police-reported alcohol data on 157,702 drivers involved in fatal motor carrier crashes between 1982 - 2005 using Fatality Analysis and Reporting System (FARS) data. Drivers were categorized as motor carrier drivers if they operated a vehicle with a gross vehicle weight rating of greater than 26,000 pounds. Otherwise, they were classified as non motor carrier drivers. The sensitivity and specificity of police-reported alcohol involvement were estimated for both driver types.

Results

Of the 157,702 drivers, 18% had no alcohol information, 15% had BAC results, 42% had police-reported alcohol data, and 25% had both. Alcohol information varied significantly by driver, crash, and vehicle characteristics. For example, motor carrier drivers were significantly more likely (51%) to have BAC testing results compared to non motor carrier drivers (31%) (p < 0.001). The sensitivity of police-reported alcohol involvement for a BAC level ≥ 0.08 was 83% (95% CI 79%, 86%) for motor carrier drivers and 90% (95% CI 89%, 90%) for non motor carrier drivers. The specificity rates were 96% (95% CI 95%, 96%) and 91% (95% CI 90%, 91%), respectively.

Conclusions

The sensitivity and specificity of police-reported alcohol involvement are reasonably high for drivers involved in fatal motor carrier crashes. Further research is needed to determine the extent to which the accuracy of police-reported alcohol involvement may be overestimated because of verification bias.

Impact on the Industry

Based on the results of this study, the federal government should continue to work with states to strengthen their strategies to increase chemical testing of all drivers involved in fatal crashes.     

The relationship between blood alcohol concentration (BAC), age, and crash risk

PROBLEM: The role of age (youth and driving inexperience) and alcohol as major risk factors in traffic crash causation has been firmly established by numerous studies over the past 50 years. Less well established is how the two variables interrelate to influence crash risk. Some investigations have hypothesized an interactive or synergistic effect in which young drivers with less experience and a greater tendency to take risks are more adversely affected at lower blood alcohol concentrations (BACs) than are older drivers. The evidence for this hypothesis is mixed. Resolution of this issue has important implication for developing countermeasures directed at the young driver crash problem. METHOD: Case control data previously collected in Long Beach and Fort Lauderdale were reanalyzed using a more sensitive method for detecting interaction effects than used in the original analysis. A conditional logistic regression analyses found a highly significant agexBAC interaction (P<.0001) involving differences between drivers under 21 and those 21 and older. DISCUSSION: The results clearly indicate that positive BACs in drivers under 21 are associated with higher relative crash risks than would be predicted from the additive effect of BAC and age. It is likely that two mechanisms are operating to cause the interaction. First, it seems likely that the crash avoidance skill of young novice drivers would be more adversely affected by alcohol due to their driving inexperience, immaturity, and less experience with alcohol. Second, drivers under 21 who choose to drink and to drive after drinking probably have pre-existing characteristics that predisposed them to risk taking and crash involvement apart from any increased vulnerability to alcohol impairment. IMPACT ON INDUSTRY: The results support increased enforcement of zero-tolerance BAC laws for minors.     

Transdermal alcohol monitoring combined with contingency management for driving while impaired offenders: A pilot randomized controlled study

Objectives: In a pilot randomized controlled trial of contingency management (CM) and transdermal alcohol monitoring (TAM) with offenders driving while impaired by alcohol (DWI), perceptions regarding the acceptability of a TAM device, recruitment issues, and the impact of CM and TAM on alcohol use over a 6-week period were evaluated. The results aimed to inform the design of future trials and programs involving CM and TAM for DWI remediation.

Methods: TAM devices were affixed to 37 voluntary, community-recruited male DWI offenders with problem alcohol use. They were randomized to one of 3 groups: (1) CM; (2) alcohol use feedback (FB); and (3) TAM device only (CTL). Quantitative and qualitative data were gathered on the acceptability of TAM devices and recruitment, and alcohol use was monitored via TAM and self-report.

Results: The TAM device was perceived positively, with benefits for reducing drinking noted. Nevertheless, some of its inconveniences appeared to influence participant recruitment and attrition, including its large size and limited water resistance. TAM data revealed a significant main effect of time for reduction in weekly peak transdermal alcohol concentration (P = .02), with a decrease between means of weeks 1 and 6 (M = 0.15, SE = 0.02 vs. M = 0.09, SE = 0.02; P = .005). No significant group effect was detected.

Conclusions: TAM is a viable adjunct to CM with DWI offenders, though the TAM device used here may influence both study recruitment and adherence. These findings can guide the design of future studies into CM and TAM for DWI remediation.     

Effect of alcohol use on accelerating and braking behaviors of drivers

Objective: The present study examines the accelerating and braking behaviors of drivers at different blood alcohol concentrations (BACs) in heterogeneous driving conditions using driving simulator experiments.

Methods: Eighty-two licensed drivers performed simulated driving in a rural road environment designed in the driving simulator at 4 BAC levels: 0.00, 0.03, 0.05, and 0.08%. Driving performance was analyzed using vehicle control variables such as mean acceleration and mean brake pedal force. Generalized linear mixed models were developed to quantify the effect of different alcohol levels and explanatory variables such as driver’s age, gender, and other factors on the driving performance indicators.

Results: Alcohol use was reported as a significant factor affecting the accelerating and braking performance of drivers. The acceleration model results indicated that drivers’ mean acceleration increased by 0.013, 0.026, and 0.027 m/s² for BAC levels of 0.03, 0.05, and 0.08%, respectively. Results of the brake pedal force model showed that drivers’ mean brake pedal force increased by 1.09, 1.32, and 1.44 N for BAC levels of 0.03, 0.05, and 0.08%, respectively. Age was a significant factor in both the models where a 1-year increase in driver age resulted in a 0.2% reduction in mean acceleration and a 19% reduction in mean brake pedal force. Driving experience could compensate for the negative effects of alcohol to some extent while driving.

Conclusions: The findings of the present study revealed that drivers tend to be more aggressive and impulsive under the influence of alcohol, which deteriorates their driving performance. Impairment in accelerating and braking behaviors of drivers under the influence of alcohol leads to increased crash probabilities. The conclusions may provide reference in making countermeasures against drinking and driving and contribute to traffic safety.     

Postural Stability of Sitting Women

The study examined the utility of stabilometric dimensions and explored whether the changes in sitting postures were manifested in functional measures of postural control. Eleven women participated in the study, which used 11 chair sitting postures: arms on laps or arms right angled; armrest at a height of 17, 20 and 23 cm; with or without backrest; slouch or straight back; legs right angled at knees or crossed legs. The backrest and armrest shifted 16.3% of body weight from a seat pan. The characteristics of stabilometric dimensions evaluated the influence of seat components and sitting behaviour on postural balance. The study attempted to evaluate stability and its application in human-seat interface design.     

Postural Loading Assessment in Assembly Workers of an Iranian Telecommunication Manufacturing Company

Background. Changes in industries and work practices have coincided with work-related musculoskeletal disorders (MSDs). This study was conducted to determine the prevalence of MSDs and to assess postural loading in assembly workers of an Iranian telecommunication manufacturing company. Methods. Data were collected from 193 randomly selected workers in 4 units of the company. The Nordic musculoskeletal disorders questionnaire and the UBC ergonomic checklist were used as data collection tools. Loading on the upper body assessment (LUBA) was used to assess postural loading. Results. Lower back symptoms were the most prevalent problems among the workers (67.9%). LUBA showed that most assembly workers (94.3%) had experienced considerable and high postural loading (postural load index, PLI > 5). Regression analyses revealed that lighting, rotation, contact stress, repetition, gender and age were factors associated with symptoms. Conclusion. Work-related MSDs occurred at a high rate among workers. Postural loading requires consideration. Any ergonomic intervention should focus on eliminating ergonomic factors associated with symptoms.     

Effect of External Load at Varying Hand Positions on Perceived Discomfort

The purpose of this study was to assess the effect of external load at varying hand positions on discomfort, and to provide a new classification of external load. An experiment was carried out in which 16 postures with an external load of 0, 1.5, 3 kg were tested. The postures were controlled by 2 independent variables of hand distance and hand height. The subjects were instructed to rate their perceived discomfort with magnitude estimation after holding a given posture for 1 min. Analysis of variance (ANOVA) exhibited that the main effects of the 3 independent variables were statistically significant for discomfort. Discomfort increased linearly with external load and hand distance. Hand height showed a quadratic relation with discomfort, which exhibited a slightly different trend from hand distance and external load. Based on the results, a new classification of external load was proposed with 3 classes grouped by perceived discomfort.     

The Relationships Between Biomechanical and Postural Stresses,Musculoskeletal Injury Rates,and Perceived Body Discomfort Experienced by Industrial Workers: A Field Study

A combination of archival, subjective, and observational field data collection methods were used to investigate the relationship between biomechanical and postural stresses, and the resulting physical strain experienced by industrial workers of a packaging plant. Assessment of physical strain was based on the number and incidence rate of Occupational Safety and Health Administration (OSHA)-reportable injuries that were recorded over a period of 27 months, and based on the self-reported ratings of perceived body discomfort. Both the biomechanical and postural stresses correlated with the musculoskeletal injury rate. The results illustrate the usefulness of postural and biomechanical analyses for assessing the risk of injury in industry.     

Characteristics of Muscular Load in Computer Data Entry Workers Assessed by EMG and Postural Angles

The goal of this study was to characterize the muscular load in computer data entry workers. Electromyography (EMG) parameters of trapezius muscle and postural angles of head, arm, and back were chosen as indicators of musculoskeletal load. The examination was done according to the methods and protocol of international MEPS studies (the “Musculoskeletal, Visual, and Psychosocial Load in VDT [Video Display Terminal] Operators in Optimized Environment” international program). The musculoskeletal load during routine VDT data entry work performed by a group of 36 women was assessed on the basis of 1-hr physiometer recordings. Results show that the musculoskeletal load associated with data entry is relatively high compared to other VDT operators’ tasks described in the literature. An analysis of the measured parameters shows that most of the time women worked with a muscular load higher than optimal. It is postulated that the main reason for the heavy musculoskeletal load was improper posture compelled by unergonomic spatial configuration of work stands.     

隔爆低频永磁同步电动机矢量控制方式研究

为了解决隔爆低频（TBD）型永磁同步电动机（PMSM）中如何利用精确的转子位置和速度信号去实现磁场定向的问题,分析了永磁同步电动机的矢量控制理论,讨论了无传感器矢量控制方案,提出了基于空间电压矢量脉宽调制（SVPWM）技术的矢量控制方案,采用TMS320LF2812为核心处理器进行矢量控制系统的硬件设计,采用DSP编程实现该系统的软件设计,进行了基于无传感器矢量控制系统的仿真研究及实验波形分析。结果表明：无传感器矢量控制方案具有很好的动态特性,能够稳定运行,满足驱动系统的要求。     

软弱基底排土场变形破坏治理措施研究

针对软弱基底露天矿排土场普遍存在的变形破坏问题,结合胜利东二露天矿南排土场南帮边坡的工程实际,基于极限平衡理论,给出了通过探槽及滑坡变形反分析综合确定基底赋存条件及抗剪强度指标的方法;提出了对软弱基底排土场的变形治理措施;根据已有监测数据,对南帮边坡治理效果进行了评价。结果表明:在实施削坡减载措施后,各地表监测点的累计位移趋于平缓,边坡治理措施效果明显,解决了胜利东二露天矿迫切的安全问题,为同样具有软弱基底的其他露天矿排土场变形及破坏治理提供了指导。     

The influence of alcohol on pedestrians: A different approach to the effectiveness of the new traffic safety law

Objective: The aim of this study was to explore the effects of the new traffic safety law on pedestrian mortality by exploring hazardous behaviors of pedestrians in terms of alcohol use and blood alcohol concentration (BAC).

Methods: A retrospective autopsy study was performed, covering a 7-year period (from 2006 to 2012), including cases of fatally injured pedestrians who died at the scene of the incident. Blood samples obtained from the femoral vein during autopsy were analyzed for BAC. The entire sample was divided into 2 groups. The first included cases from 2006 to 2009, at which time the old traffic safety law was in force, and the second included cases from 2010 to 2012, under the new traffic safety law.

Results: A total of 247 cases were examined, covering a 7-year period. The average age was 57.5 ± 19.7 years (median 61.0 years) with a significant male predominance of 147 men to 100 women. This predominance also applied to alcohol use (54 vs. 13). The results show a significant decrease in the total annual number of fatally injured pedestrians, starting from 2009, compared to previous years, reaching a low in 2010, one year after implementation of the new traffic safety law. In contrast, the proportion of alcohol-intoxicated pedestrians showed no significant difference in the years preceding and following the new traffic safety law, nor did the annual distribution of BAC or mean BAC before and after application of the new law.

Conclusion: The present study indicates that the new traffic safety law has been quite effective in reducing pedestrian mortality. However, alcohol consumption and intoxication in pedestrians remains a fairly important factor in motor vehicle accidents involving pedestrians, because the proportion of pedestrians positive for alcohol, the proportion of severely intoxicated pedestrians with BAC > 1 g/L, and annual mean BAC have remained unchanged.     

Alcohol policy and fatal alcohol-related crashes in Finland 2000–2016

Objective: The purpose of this study was to explore the relationship between annual alcohol consumption per capita/alcohol price index and the number of alcohol-related fatal motor vehicle accidents (AFMVAs). We were particularly interested in whether a tax reduction in 2004 increased the number of alcohol-related accidents.

Method: The data consisted of all fatal motor vehicle accidents (FMVAs) during the years 2000–2016 obtained from a database maintained by the Finnish Crash Data Institute (OTI). The data included all fatally injured drivers. We compared the OTI data to official statistics on annual alcohol consumption and the alcohol price index.

Results: There were 3,447 fatally injured drivers, of which 25% (n = 869) were intoxicated (blood alcohol concentration [BAC] ≥ 0.05%). After the reduction of the alcohol tax in 2004, the alcohol consumption rose 12.4% from 2003 to 2005 and AFMVAs rose 38%. There was a strong correlation (r = 0.7000, P < .018) between the recorded consumption of alcohol and the number of AFMVAs. There was a strong negative correlation between AFMVAs and the combined (retail + restaurant sales) alcohol price index (r = ?0.7863, P = .0005). A linear mixed-effects model showed that a 1-L increase in total alcohol consumption per capita per year increases AFMVAs by 10.6 and a one-unit increase in the price index decreases AFMVAs by 1.8 per year.

Conclusions: The correlation between alcohol consumption and alcohol-related crashes should be considered when making political decisions regarding alcohol price and availability. Any further liberalization of the alcohol policy would likely lead to an increase in alcohol-related fatal motor vehicle accidents. Similar consequences are likely to occur with drugs. Alcohol price policy is an effective way to improve road safety, but other measures taken to prevent FMVAs also seem to reduce the prevalence of AFMVAs.     

Are you okay to drive? Commuting behavior and blood alcohol concentrations among restaurant diners

Objective: Drink driving is widely recognized as a major road safety problem. In Australia, health promotion messages encourage monitoring the number of standard drinks consumed prior to driving. This pilot research aimed to investigate commuting behavior and blood alcohol concentration (BAC) of diners, including intended drivers, at Sunshine Coast restaurants.

Methods: Five hundred and forty-four diners (n = 260 males) consented to participate in a brief interview and to use a breathalyzer device to measure their BAC.

Results: Forty percent of participants advised they don't drink and drive (34% of males, 45% of females; 67.25% of <17–20 years, 30.5% of 50–59 years), and of the remaining participants, 75% advised they count the number of their drinks (69% of males, 84% of females; 32% of <17–20 years, 82% of 50–59 years), while 10% of participants monitored their BAC by how they were feeling (12% of males, 6% of females). Thirty-seven percent of participants said it was easy/very easy to estimate their BAC (41% of males; 33% of females; 21% of <17–20 years, 43% of 50–59 years). The actual BAC was less than expected for 56% of participants, with one-third underestimating BAC and some intended drivers having an actual BAC in excess of the 0.05 limit.

Conclusions: Given the proportion of diners who reported they count the number of drinks, or use feelings as a way to gauge BAC, coupled with the considerable proportion who underestimated their BAC, a safer public health message is to avoid driving if you intend to drink. In addition, targeted intervention for experienced drivers (and, arguably, drinkers) appears warranted, as every participant aged less than 21 years who stated he or she would drive home indeed had a zero BAC. Interestingly every female driver who stated she would be driving home also had a legal BAC, suggesting gender-specific intervention.