Gap acceptance and risk-taking by young and mature drivers, both sober and alcohol-intoxicated, in a simulated driving task

A single-blind randomized study was conducted on young (18–21 years, n = 16) and mature (25–35 years, n = 16) drivers to assess how age, combined with a modest dose of alcohol (0.7 g/kg for males and 0.6 g/kg for females), influenced performance on a driving simulator. The driving tasks included detecting the presence of a vehicle on the horizon as quickly as possible, estimating the point on the road that an approaching vehicle would have passed by the participants’ vehicle (time-to-collision) and overtaking another vehicle against a steady stream of oncoming traffic. The results of the vehicle detection task showed that detection times were significantly slower with maturity, alcohol consumption and lower approaching vehicle speeds (50 kph), particularly on curved sections of road. Approaching vehicle speed was also found to significantly influence time-to-collision (TTC) judgments, such that faster approach speeds led to less underestimated (and therefore riskier) judgments of TTC than slower speeds. In the overtaking task, mature participants demonstrated impaired discrimination skills with varying approaching vehicle speeds, while young participants recorded significantly slower speeds while overtaking a vehicle, thus increasing the time that they spent in the opposing lane. In conclusion, young and mature drivers demonstrated pivotal differences in behavior in this study. Young drivers showed a greater tendency to engage in risky driving, while experienced drivers appeared to be more susceptible to perceptual influences. Overall, alcohol consumption impaired a driver's ability to divide attention, but had little effect on decision-making processes.     

Predictors of driving after alcohol and drug use among adolescents in Valencia (Spain)

Background

Driving under the influence of alcohol and drugs has been identified as a risk factor for road traffic crashes. We have assessed the prevalence and predictor factors for driving after alcohol and drug use by adolescents.

Methods

A cross-sectional survey involving 11,239 students aged 14–18 years from 252 private and public schools in the Valencia region of Spain was conducted. The prevalence and predictors of driving after alcohol use, alcohol and drug use, or drug use during the previous 6 months were measured.

Results

Of the students who reported driving (20%), 45.1% indicated driving after alcohol and drug use. The consumption of various drugs was higher among students who drove a vehicle compared with those who did not. The likelihood of driving after consuming alcohol, or alcohol and drugs, increased in line with the number of standard drink units per week, reports of any lifetime alcohol- or drug-related problems, and poor family relationship. In addition, masculine gender and early alcohol use increased the likelihood of driving after consuming alcohol.

Conclusions

Driving after alcohol and drug use is quite prevalent among adolescents in the Valencia region of Spain. There is a need for implementation of targeted policies for adolescents. This should focus on education and information on alcohol/drug use and driving.     

Identifying factors that predict persistent driving after drinking,unsafe driving after drinking,and driving after using cannabis among young adults

The main aim of this study was to identify adolescent/young adulthood factors that predicted persistent driving after drinking, persistent unsafe driving after drinking, and persistent cannabis use and driving among young adults. It was a longitudinal study of a birth cohort (n=933, 474 males and 459 females) and was based on data collected at ages 15, 18, 21 and 26 years. At each of these ages members of the cohort attended the research unit for a personal interview by a trained interviewer, using a standardised questionnaire. For this study, the data for the outcome measures (persistent driving after drinking, persistent unsafe driving after drinking, and persistent driving after using cannabis) were obtained at ages 21 and 26 years. The main explanatory measures were collected at ages 15, 18, 21 years and included demographic factors (academic qualifications, employment, parenting); personality measures; mental health measures (substance use, cannabis dependence, alcohol dependence, depression); anti-social behaviour (juvenile arrest, aggressive behaviour, court convictions); early driving behaviour and experiences (car and motorcycle licences, traffic crashes).The analyses were conducted by gender. The results showed that females who persisted in driving after drinking (13%, n=61) were more likely than the others to have a motorcycle licence at 18. The males who persisted in driving after drinking (28%, n=135) were more likely than the other males to have some school academic qualifications and to be employed at age 26. Compared to the other males, those who persisted in unsafe driving after drinking (4%, n=17) were more likely to be aggressive at 18 and alcohol dependent at 21. Only six (1%) females persisted in unsafe driving after drinking so regression analyses were not conducted for this group. For persistent driving after using cannabis, the univariate analyses showed that females who persisted with this behaviour tended to have high substance use at 18, cannabis dependence at 21, police contact as a juvenile, and to be a parent at 21. For this group, because of the small numbers (3%, n=13) multivariate analyses were not appropriate. For the males who persisted in driving after using cannabis (14%, n=68) a wide range of variables were significant at the univariate stage. The multivariate analysis showed that the most important factors were dependence on cannabis at 21, at least one traffic conviction before 21, a non traffic conviction before 18, and low constraint at 18. CONCLUSION: These results show different characteristics were associated with persistence in each of these outcome behaviours. This indicates that different approaches would be required if intervention programmes were to be developed to target these behaviours.     

Drug and alcohol use among drivers admitted to a Level-1 trauma center

The purpose of this research was to determine the incidence and prevalence of drug use, alcohol use, and the combination of drug and alcohol use among motor vehicle crash (MVC) victims admitted to a Level-1 trauma center. In a 90-day study, nearly two-thirds of trauma center admissions were victims of motor vehicle crashes. Blood and urine was collected from 168 MVC victims of whom 108 were identified as the driver in the crash. Toxicology results indicated that 65.7% of drivers tested positive for either commonly abused drugs or alcohol. More than half of the drivers tested positive for drugs (50.9%) other than alcohol, with one in four drivers testing positive for marijuana use. About one-third of those using drugs had also been drinking, but alcohol was detected in only 30.6% of all injured drivers. Within the total MVC patient pool, passenger drug/alcohol use was equivalent to the driver population; however, injured pedestrians had higher rates of alcohol only than other MVC victims. There were no significant differences in drug and alcohol use between MVCs and trauma admissions of other causes. Of the patients with positive toxicology results, less than half (42%) were referred for evaluation for substance abuse disorders.     

Factors associated with alcohol and drug use among traffic crash victims in southern Brazil

Objective

To investigate the prevalence of and factors associated with alcohol- or drug-related traffic crashes (TC) in a sample of TC victims who were admitted to the two emergency rooms of Porto Alegre in southern Brazil.

Methods

A cross-sectional study with consecutive samples was used. Victims of non-fatal TCs (as drivers, passengers or pedestrians) who had presented at emergency rooms during the 45 days of data collection were selected. Subjects participated in a structured interview, were breathalyzed and underwent salivary drug testing. A multinomial logistic regression model was used to verify factors associated with alcohol or drug use.

Results

Of the 609 victims who participated in the interview, 72% were male, and the median age was 29 years (interquartile range 23.0–40.0 years). The drivers were mostly men (p < 0.001), with a higher binge drinking rate (p = 0.003) and marijuana use (p = 0.005) than seen in pedestrian and passengers. The prevalence of a positive blood alcohol concentration (BAC) ranged from 7.8% among the drivers to 9.2% among the pedestrians (p = 0.861), and the cannabis prevalence was 13.3% among the drivers. The variables associated with an alcohol-related accident were binge drinking in the prior 12 months (OR 2.4; CI 95% 1.1–5.1) and coming from a party/bar (OR 8.7; CI 95% 2.8–26.7). Alcohol abuse or dependence increased by 5.2-fold the chance of another substance-related TC.

Conclusion

The large number of individuals found in TC-related emergency room visits in a short time frame is evidence of the Brazilian epidemic of TC. The data showed that alcohol abuse or dependence also increases the risk of intoxication by other drugs, and they point to alcohol and drug use as a major problem requiring specific TC-related public policies and law enforcement.     

Superstition,risk-taking and risk perception of accidents among South African taxi drivers

The aim of this study was to investigate taxi drivers' superstition and risk perception of accidents as well as risk-taking in an urban area in South Africa. One hundred and thirty drivers of minibuses, so-called "taxis" were interviewed on the basis of: (1) a superstition scale; (2) a risk-taking scale; (3) a list of perceived causes of road traffic accidents. Drivers showed largely superstitious attitudes and expressed a high degree of risk-taking behavior.Superstition was positively correlated with the number of self-reported accidents the drivers had been involved in and the number of accidents they had witnessed. Path analysis revealed a direct path from superstition to accident involvement while the influence of formal education was negligible. Risk-taking was inversely correlated with driving experience and the number of accidents witnessed but not so with the number of accidents involved in. There was no clear pattern of associations between superstition and risk-taking and perceived causes of accidents. Superstition and risk-taking were slightly and inversely correlated with each other. It is concluded that superstition represents an attitude that is associated with a driver's accident risk, and further research on superstitious attitudes among South African drivers is advocated.     

Self-regulatory driving practices among older adults: health, age and sex effects

The purpose of this study was to better understand how older adults self-regulate driving, and to identify differences by age, sex, and health-related functioning. Michigan drivers over age 64 were surveyed by telephone (n=961, age [mu=74.2, sigma=5.8], 56% female) about their driving-related behaviors, physical functioning, and health. Respondents were presented with scenarios involving driving to an important appointment under adverse conditions (rainy stormy weather, on alternate route in heavy freeway traffic, 200-mile trip on unfamiliar roads). Generalized logit models examined outcomes for each scenario: driving as usual, driving with modifications, and not driving. Results indicate that the effect of sex on self-regulation was significant and greater than that of age and physical functioning. Women were more likely to self-regulate by not driving. Odds ratios and 95% confidence limits for each scenario for women vs. men are 6.8 (3.8-2.0), 6.5 (3.6-12.0), and 17.7 (11.0-28.6). The effect of sex on self-regulation by modifying driving was smaller and significant only in scenarios 2 and 3. Women were more likely then men to modify driving for scenario 2 (odds ratio, 3.0 (2.0-4.5)) and scenario 3 (odds ratio 4.4 (3.1-0.1)). Overall, the study finds the relative effect of sex on self-regulation greater than that of age and physical functioning for conditions examined.     

Effects of THC on driving performance, physiological state and subjective feelings relative to alcohol

BACKGROUND: The effects of marijuana or THC on driving has been tested in several studies, but usually not in conjunction with physiological and subjective responses and not in comparison to alcohol effects on all three types of measures. OBJECTIVE: To assess the effects of two dosages of THC relative to alcohol on driving performance, physiological strain, and subjective feelings. METHOD: We tested the subjective feelings and driving abilities after placebo, smoking two dosages of THC (13 mg and 17 mg), drinking (0.05% BAC) and 24 h after smoking the high dose THC cigarette, while monitoring physiological activity of the drugs by heart rate. Fourteen healthy students, all recreational marijuana users, participated in the study. RESULTS: Both levels of THC cigarettes significantly affected the subjects in a dose-dependent manner. The moderate dose of alcohol and the low THC dose were equally detrimental to some of the driving abilities, with some differences between the two drugs. THC primarily caused elevation in physical effort and physical discomfort during the drive while alcohol tended to affect sleepiness level. After THC administration, subjects drove significantly slower than in the control condition, while after alcohol ingestion, subjects drove significantly faster than in the control condition. No THC effects were observed after 24 h on any of the measures.     

Drug use and fatal motor vehicle crashes: A case-control study

Drugged driving is a serious safety concern, but its role in motor vehicle crashes has not been adequately studied. Using a case-control design, the authors assessed the association between drug use and fatal crash risk. Cases (n = 737) were drivers who were involved in fatal motor vehicle crashes in the continental United States during specific time periods in 2007, and controls (n = 7719) were participants of the 2007 National Roadside Survey of Alcohol and Drug Use by Drivers. Overall, 31.9% of the cases and 13.7% of the controls tested positive for at least one non-alcohol drug. The estimated odds ratios of fatal crash involvement associated with specific drug categories were 1.83 [95% confidence interval (CI): 1.39, 2.39] for marijuana, 3.03 (95% CI: 2.00, 4.48) for narcotics, 3.57 (95% CI: 2.63, 4.76) for stimulants, and 4.83 (95% CI: 3.18, 7.21) for depressants. Drivers who tested positive for both alcohol and drugs were at substantially heightened risk relative to those using neither alcohol nor drugs (Odds Ratio = 23.24; 95% CI: 17.79, 30.28). These results indicate that drug use is associated with a significantly increased risk of fatal crash involvement, particularly when used in combination with alcohol.     

Associations between driving under the influence of alcohol or drugs,speeding and seatbelt use among fatally injured car drivers in Norway

Since 2005, all fatal road traffic crashes in Norway have been analyzed in-depth by multidisciplinary investigation teams organized by the Norwegian Public Roads Administration (NPRA). During the period 2005–2010, 608 drivers of cars or vans were killed in road traffic crashes. Blood samples were collected from 372 (61%) of the drivers and analyzed for alcohol and a large number of psychoactive drugs at the Norwegian Institute of Public Health (NIPH). After coupling the analytical results with the NPRA crash database, 369 drivers with a fatal outcome were identified and included. Alcohol or drug concentrations in blood above the legal limits were found in 39.8% of the drivers who were investigated for alcohol or drug impairment; 33.9% had blood alcohol concentrations above 0.5 g/L or concentrations of drugs above the equivalent Norwegian legal impairment limits or concentrations of amphetamines above 200 μg/L. Among drivers with a fatal outcome who had been impaired by alcohol or drugs, 64.6% were unbelted and 71.7% were speeding when the crash occurred; whereas 24.2% and 33.2% of the sober drivers were unbelted or speeding, respectively. Statistically significant associations were found between impairment by alcohol or amphetamines and driving unbelted or speeding. Excessive speeding is one of the main reasons for road traffic crashes and together with being unbelted the main reasons for a fatal outcome. This behavior might in many cases be due to increased risk-taking or negligence of safety measures as a result of alcohol or drug use.     

The effect of alcohol, THC and their combination on perceived effects, willingness to drive and performance of driving and non-driving tasks

Background

Driving under the influence of drugs (DUID) is one of the main causes of car accidents. Alcohol and marijuana are the most popular drugs among recreational users. Many classify these drugs as “Light” drugs and therefore allow themselves to drive after consuming them.

Objective

The study had two main objectives: 1) to investigate the effect of alcohol (BAC = 0.05%), THC (13 mg) and their combination on driving and non-driving tasks. 2) to investigate the extent to which people are willing to drive based on their subjective sensations and their perceived effects of the drugs.

Method

7 healthy men and 5 healthy women, ages 24-29, all recreational users of alcohol and marijuana, completed 5 experimental sessions. Sessions included: drinking and smoking placebo, drinking alcohol and smoking placebo, drinking placebo and smoking THC, drinking alcohol and smoking THC, drinking placebo and smoking placebo 24 hours after drinking alcohol and smoking THC. Three types of measures were used: subjective perceptions (with questionnaires), performance parameters of the driving and non-driving tasks (arithmetic task and a secondary target detection task) and physiological changes (heart rate).

Results

Overall, the combination of alcohol and THC had the most intense effect after intake. This effect was reflected in performance impairments observed in the driving and non-driving tasks, in the subjective sensations after intake, and in the physiological measures. Despite significant differences in the size of the effects after the various treatments, there were no differences in the distances subjects were willing to drive while under the influence on each of the treatments.     

The effect of the new traffic law on drinking and driving in São Paulo,Brazil

Objective

To present data on drinking and driving in the city of São Paulo, Brazil, and the effects of the new traffic law (Law 11,705) introduced in 2008.

Methods

A cross-sectional study was performed using a questionnaire and passive breath test data to study the prevalence of drinking and driving and the association of drinking and driving with background characteristics and drinking patterns on two separate occasions. The data were gathered from 2007 to 2009 through roadside surveys conducted on busy public roads. Four thousand two-hundred thirty-four (4234) drivers were approached, before and after prohibition, from the south, north, east, and west regions of the city of São Paulo, located in southeastern Brazil, including cars, motorcycles, and utility vehicles. A total of 3854 (91%) consented to participate in the survey and answered the questionnaire. Out of this group, 3229 (84%) agreed to take the passive breathalyzer test.

Results

Logistic regression analyses controlling for gender and age was used to predict a positive breath test (above 0.2 g/l) and the impact of the new law. These analyses indicated that, after the passage of the new traffic law, there was a 45% decrease in driver behavior with positive breathalyzer results. Having a pattern of alcohol consumption of at least once a week and the habit of drinking and driving are risks for a positive breathalyzer.

Conclusions

Despite the decline in the frequency of motorists driving under the influence of alcohol, traffic-related injuries and deaths, after the new law, other measures for a public policy related to alcohol should be considered based on scientific evidence, consistency of action, clear goals, community support, and greater reliability in the laws.     

The relationship between cognitive performance,perceptions of driving comfort and abilities,and self-reported driving restrictions among healthy older drivers

The objective of the present study was to examine the relationship between cognitive performance, driver perceptions and self-reported driving restrictions. A cross-sectional analysis was conducted on baseline data from Candrive II, a five-year prospective cohort study of 928 older drivers aged 70–94 years from seven cities. Cognitive performance was assessed using the Montreal Cognitive Assessment (MoCA) as well as the Trail Making Test, parts A and B. Driver perceptions were assessed using the Day and Night Driving Comfort Scales and the Perceived Driving Abilities scale, while driving practices were captured by the Situational Driving Frequency and Avoidance scales, as well as the Driving Habits and Intentions Questionnaire. The baseline data indicates this cohort is largely a cognitively intact group. Univariate regression analysis showed that longer Trails A and B completion times were significantly, but only modestly associated with reduced driving frequency and perceived driving abilities and comfort, as well as a significant tendency to avoid more difficult driving situations (all p < .05). Most of these associations persisted after adjusting for age and sex, as well as indicators of health, vision, mood and physical functioning. Exceptions were Trails A and B completion times and situational driving frequency, as well as time to complete Trails B and current driving restrictions. After adjusting for the confounding factors, the total MoCA score was not associated with any of the driving measure scores while the number of errors on Trails A was significantly associated only with situational driving frequency and number of errors on Trails B was significantly associated only with situational driving avoidance. Prospective follow-up will permit examination of whether baseline cognition or changes in cognition are associated with changes in driver perceptions, actual driving restrictions and on-road driving outcomes (e.g., crashes, violations) over time.     

Alcohol consumption,helmet use and head trauma in cycling collisions in Germany

Cycling, being easy, inexpensive and healthy, is becoming one of the most popular means of transport. Cyclists, however, are among the most vulnerable road users in traffic collisions.     

Self-rated driving habits among older adults with clinically-defined mild cognitive impairment,clinically-defined dementia,and normal cognition

Older adults with clinically-defined dementia may report reducing their driving more than cognitively normal controls. However, it is unclear how these groups compare to individuals with clinically-defined mild cognitive impairment (MCI) in terms of driving behaviors. The current study investigated self-reported driving habits among adults age 60 and older with clinical MCI (n = 41), clinical mild dementia (n = 40), and normal cognition (n = 43). Participants reported their driving status, driving frequency (days per week), and how often they avoided accessing the community, making left turns, driving at night, driving in unfamiliar areas, driving on high-traffic roads, and driving in bad weather. After adjusting for education, a MANCOVA revealed that participants with MCI and dementia avoided unfamiliar areas and high-traffic roads significantly more than normal participants. Participants with dementia also avoided left turns and accessing the community more than those with normal cognition and MCI (p < 0.05 for all). The other driving variables did not significantly differ between groups. Thus, older adults with clinically-defined MCI, as well as those with dementia, avoided some complex driving situations more than cognitively intact adults. However, all diagnostic groups had similar rates of driving cessation and frequency. Future research should examine the safety implications of such findings.     

Alcohol, illicit and non-illicit psychoactive drug use and road traffic injury in Thailand: A case-control study

The objective of this study was to determine the relationship between alcohol use, psychoactive drug use and road traffic injury (RTI). A case-control study was conducted among drivers in Bangkok, Thailand. Two hundred cases and 849 controls were enrolled between February and November 2006. Cases who sustained a RTI were matched with four controls recruited from petrol stations within a 1-km radius of the reported crash site of the case.A positive alcohol breath test (≥50 mg/dl), and positive tests for the presence of illicit (amphetamine, cocaine, marijuana) and non-illicit psychoactive drugs (antihistamine, benzodiazepine, antidepressants), using gas chromatography/mass spectrometry (GC/MS) were documented as primary measures.There were significantly higher odds of an alcohol breath test ≥50 mg/dl (adjusted odds ratio (OR) 63.6 (95% CI: 25.5-158.9)), illicit psychoactive drugs (adjusted OR 3.4 (95% CI: 1.7-6.6)) and non-illicit psychoactive drug (adjusted OR 3.1 (95% CI: 1.5-6.3)) among cases than controls.Even though driving under the influence of psychoactive drugs has been significantly linked to RTI, its contribution to road safety is much lower than driving under the influence of alcohol. With limited resources, the priority for RTI prevention should be given to control of driving under the influence of alcohol.     

Social, behavioral and driving characteristics of injured pedestrians: a comparison with other unintentional trauma patients

Pedestrian injuries represent 11% of all motor vehicle related injuries in the USA. This study attempts to define the epidemiology of the pedestrian victim. Patients admitted to a regional adult trauma center were interviewed and evaluated for substance abuse. Pedestrians were compared with the remaining unintentional trauma patients with regard to demographics, socioeconomics, possession of a driver's license, injury prone behaviors, risk taking dispositions, and BAC levels using the Student's t-test and Pearson's chi2 statistic (alpha=0.05). Multivariate logistic regression models were built with pedestrian mechanism as the outcome. When compared to the remaining unintentional trauma population (N=661), pedestrians (N=113) were significantly more likely to be black, not married, unemployed, binge drinkers, alcohol dependent, drug dependent, BAC+, to have a low income, low educational achievement, younger age, and to not have a driver license. Black race, unemployment of 1 year or more, never licensed, lapsed license, revoked license and BAC>200 mg/dl showed statistical significance in the multiple logistic regression. Pedestrians represent a sub-population with a low socioeconomic status and high incidence of substance abuse. Unemployment, not having a driver's license, black race, and a BAC>200 mg/dl were strongly linked to being an injured pedestrian.     

Synthesis, swelling and drug release behavior of poly(N,N-diethylacrylamide-co-N-hydroxymethyl acrylamide) hydrogel

In this study, poly(N,N-diethylacrylamide-co-N-hydroxymethyl acrylamide) (poly(DEA-co-NHMAA)) hydrogels were synthesized by changing the initial DEA/NHMAA mole ratio, N,N'-methylenebisacrylamide and total monomer concentration. The thermosensitive and mechanical performances were optimized by altering the above parameters. The hydrogels were characterized by using Fourier transform infrared (FTIR) spectroscope and scanning electron microscope (SEM). In comparison with the PDEA hydrogel, the equilibrium swelling ratio (ESR) and lower critical solution temperature (LCST) of the hydrogels increased with the increase of NHMAA content in the feed. The swelling kinetics was also studied. The release behaviors of the model drug, aminophylline, are found dependent on hydrogel composition and environmental temperature, which suggests that these materials have potential application as intelligent drug carriers.