The use of a virtual driving simulator has the potential to positively impact occupational medicine. Research, education, and rehabilitation can all be accomplished in a safe environment using virtual driving simulators as an alternative to on-road testing.

Clinicians and researchers rarely have the necessary simulation equipment and must rely on commercial systems. Often, the configuration of commercial systems does not necessarily meet the specific needs of the user.

A 2013 study from Germany aimed at further developing commercial car driving simulation scenarios for research in occupational medicine discovered key factors that could impact the effectiveness of virtual simulators in the industry.

Strengthening Driving Simulation Research

The purpose of the study was to refine a commercial car driving simulation for use in occupational research. Researchers tested for variables including simulator sickness, fatigue, and learned behavior to refine the simulated driving scenario for greatest effectiveness.

Ethanol was used to create a test group and a control group. As the effects of ethanol on driving are well established, this compound allowed researchers to investigate the performance of subjects during the simulation.

The study measured the effects of ethanol on accidents, braking reaction time, and tracking performance.

The study

Participants included 20 healthy young males with a mean age of 25. They were randomly dispersed into either the test group or control group.

Prior to the study, participants were given medical exams to test for visual acuity and color vision ability. All subjects were licensed for at least one year and had a minimum of 500 kilometers (approximately 310 miles) of driving experience. Because ethanol was used as a test compound all participants self-identified as social drinkers.

The driving simulator used in the study was a fixed-base model with controls similar to an automatic Ford Fiesta. A sound system generated noises related to speed and collisions.

Different scenarios were constructed to test for simulator sickness, familiarization with the simulator, training, and for two experimental night-simulated sessions.

Night scenarios were chosen to reduce the risk of simulator sickness. A video system monitored driving behavior and subject reactions.

Each training and test course began with a straight highway course where participants had to account for traffic changes and had to avoid emergency collisions testing for brake reaction time.

The highway course was followed by a rural course that included curves and also potential collision situations (deer, donkeys, and men).

Crashes and reaction time were registered. Researchers assessed lane-keeping behavior by the standard deviation in lane position (Sdlat).

During a one-hour rest period, participants either drank diluted vodka or pure orange juice. The target concentration of blood alcohol level for the test group was 0.06%.

Participants then drove an analog course. Subjective sleepiness, simulator sickness, and driving behaviors were monitored.

Findings

Subject sleepiness was highest during highway drives in both groups, especially during the second test drive. No subject had to terminate the experiment due to simulator sickness, even after alcohol consumption in the test group.

In the test group, the total number of accidents rose after ethanol consumption from 25 in the first test to 28 in the second. The control group displayed a decrease in accidents from 29 to 20.

Braking reaction time varied considerably. According to the linear mixed model, 0.1% BAC would increase the reaction time by 237 ms.

Lane-keeping behavior was lowest in the straight rural road sections and highest in the left-hand curves (the higher the Sdlat the worse the lane keeping behavior). Effects of ethanol on Sdlat differed depending on the scenario.

The Simulator Sickness Questionnaire (SSQ) was utilized and scores were relatively low and not associated with driving performance in the linear mixed models. Researchers concluded that the driving scenarios would not evoke noteworthy simulator sickness in screened young adult male subjects.

In this study, simulator sickness sensitivity increased in the highway scenarios. The straight, monotonous scenario resulted in an increased sleepiness.

“Therefore, we conclude that the increase of total SSQ scores on the highway was due to an increase in driver sleepiness. Thus, the monotonous highway drive falsely caused elevated SSQ scores with regard to possible simulator sickness,” researchers stated. “…control for possible simulator sickness should be mandatory, for it might confound the data.”

Noting that this scenario produced adequate monotony can save time in future studies in which investigators study the effects of sleepiness on driving ability.

Researchers also discovered a possible learning effect, (the mean braking time declined by 86ms in the second test drive), which must be accounted for in future studies.

Results

Results were consistent with other studies on the effects of ethanol on driving. Reduced braking reaction time after ethanol ingestion was noted. The strongest association between BAC and lane keeping behavior was observed on right-hand curves.

Finally, the difference between real life and virtual driving simulation must be taken into account. Subjects in a simulator may not fight sleepiness as they would in an on-road assessment.

“In the preliminary tests, some subjects spontaneously expressed their shock after colliding with a man, but were not disconcerted when they caused an accident with an animal,” according to the research. “Possibly, subjects of the pilot study hit the brakes stronger when a man appeared.”

Equipment limitations prevented the measurement of brake pressure over time.

“Expression of shock means an emotional engagement of subject,” researchers stated. The feeling of “presence” is an argument for the external validity of simulation.

Conclusion

Researchers noted the following findings:

• The observed ethanol effects lead to the conclusion that the applied scenario is also a suitable means to investigate the effects of other compounds such as drugs or driver sleepiness.
• The development of simulator sickness should be prevented as far as possible by creating appropriate scenarios.
• The level of drowsiness should be controlled during driving simulation.
• Possible learning behavior during the experiment should also be controlled.

DriveSafety has a number of clinical virtual driving simulators and simulation scenarios can be tailored to the needs of the occupational medicine practitioners and patients with the assistance of certified technicians.

Clinical virtual driving simulators can be useful in re-education of patients, rehabilitation, and driving fitness tests.

Schedule a call today to speak with a certified technician about the available options.