Driving Performance Under Alcohol in Simulated Representative Driving Tasks

Abstract

Comparing drug-induced driving impairments with the effects of benchmark blood alcohol concentrations (BACs) is an approved approach to determine the clinical relevance of findings for traffic safety. The present study aimed to collect alcohol calibration data to validate findings of clinical trials that were derived from a representative test course in a dynamic driving simulator. The driving performance of 24 healthy volunteers under placebo and with 0.05% and 0.08% BACs was measured in a double-blind, randomized, crossover design. Trained investigators assessed the subjects’ driving performance and registered their driving errors. Various driving parameters that were recorded during the simulation were also analyzed. Generally, the participants performed worse on the test course (P < 0.05 for the investigators’ assessment) under the influence of alcohol. Consistent with the relevant literature, lane-keeping performance parameters were sensitive to the investigated BACs. There were significant differences between the alcohol and placebo conditions in most of the parameters analyzed. However, the total number of errors was the only parameter discriminating significantly between all three BAC conditions. In conclusion, data show that the present experimental setup is suitable for future psychopharmacological research. Thereby, for each drug to be investigated, we recommend to assess a profile of various parameters that address different levels of driving. On the basis of this performance profile, the total number of driving errors is recommended as the primary endpoint. However, this overall endpoint should be completed by a specifically sensitive parameter that is chosen depending on the effect known to be induced by the tested drug.

Protocol for the development and validation of a driving simulator for evaluating the influence of drugs on driving performance

“…[25] In WIVW research, the validity was verified by measuring SDLP and the number of errors in a road tracking test involving both highway and urban traffic scenarios using BAC crossover sets of 0.00%, 0.05%, and 0.08%. [12]…”

“…Because this is an exploratory study, the sample size was set to 24 participants in reference to the sample size of previous studies conducted to confirm the validity of a DS. [6,12] The inclusion criteria are: age between 21 and 65 years; body mass index between 18.5 and 24.9 kg/m 2 ; active-type aldehyde dehydrogenase (ALDH) gene polymorphism (ALDH 2∗1/∗1); alcohol consumption >2 days a month; able to drink a prespecified amount of alcohol in 30 minutes; possession of a driver's license and driving daily for >3 years; consistent sleeping pattern (wake up between 06:00 and 09:00 am , go to bed between 21:00 and 00:00 pm ); no visual impairments; able to operate a DS with a full understanding of all DS tasks; judged by a physician as being able to participate; and able to provide written informed consent before the examination begins. The exclusion criteria are: having a disease recognized as being nonhealthy by a physician; a history of drug or food allergies; 3) serious allergic predispositions; 4) a history of stroke, head trauma, epilepsy, or malignant tumor; more than a 3-month history of sleep disorders, a medical history of sleep apnea syndrome or restless legs syndrome, or a history of hypersomnia such as narcolepsy; use of over-the-counter drugs within 1 week after starting the practice period; use of sedative hypnotics within 4 weeks after starting the practice period; experiencing more than a 6-hour time difference within 4 weeks after starting the practice period; irregular shift work and night shift work within 4 weeks after starting the practice period; experience using the same DS evaluation method as that used in the present study; a daily routine of alcohol consumption until sleep; unable to stop drinking from 2 days before until the day of the screening test, and from 2 days before hospitalization until discharge; smoking during hospitalization; donating blood within 12 weeks; use of prescription drugs within 4 weeks after starting the practice period; a diagnosis or history of alcoholism or drug dependency; positive result from a urine drug test during screening; unable or unwilling to comply with the study protocol; and judged unsuitable for participation by a physician.…”

“…In previous studies, the amount of alcohol intake has been calculated individually based on body water content. [12,13] Therefore, we decided to calculate the amount of alcohol intake based on Widmark formula using a beverage that is a mixture of 40% vodka and orange juice. Using this formula, tests are conducted in the morning and afternoon, so the following equation will be used: …”

Effects of Consuming a Low Dose of Alcohol with Mixers Containing Carbohydrate or Artificial Sweetener on Simulated Driving Performance

“…The number of participants was determined following a sample size calculation for one common simulated driving outcome measure—standard deviation of lane position (SDLP)—using power calculation software (G*Power Version 3.1.9.2, University Kiel, Germany, 2014). Kenntner-Mabiala et al [ 21 ] detected a 3.0 ± 1.1 cm increase in SDLP under a low-dose alcohol treatment (0.050% BrAC) vs. placebo with an effect size of 0.6 [ 22 ]. Using this effect size, a power (1 − β) of 0.9 and α = 0.05 (for a priori planned comparisons), the estimated total sample required was n = 32.…”

Alcohol intoxication progressively impairs drivers' capacity to detect important environmental stimuli

“…Alcohol intoxication impairs driving skills. The use of a high-level driving simulator for such studies seems likely to underestimate the effects of alcohol and drugs on driving performance (Veldstra et al, 2015;Kenntner-Mabiala et al, 2015). However, the association of intoxication and impairment in simulator performance is well-documented (e.g.…”