Gunnar D. Jenssen

Comparison of driving simulator performance with real driving after alcohol intake: A randomised, single blind, placebo-controlled, cross-over trial

The purpose of this study was to establish and validate a driving simulator method for assessing drug effects on driving. To achieve this, we used ethanol as a positive control, and examined whether ethanol affects driving performance in the simulator, and whether these effects are consistent with performance during real driving on a test track, also under the influence of ethanol. Twenty healthy male volunteers underwent a total of six driving trials of 1h duration; three in an instrumented vehicle on a closed-circuit test track that closely resembled rural Norwegian road conditions, and three in the simulator with a driving scenario modelled after the test track. Test subjects were either sober or titrated to blood alcohol concentration (BAC) levels of 0.5g/L and 0.9g/L. The study was conducted in a randomised, cross-over, single-blind fashion, using placebo drinks and placebo pills as confounders. The primary outcome measure was standard deviation of lateral position (SDLP; weaving). Eighteen test subjects completed all six driving trials, and complete data were acquired from 18 subjects in the simulator and 10 subjects on the test track, respectively. There was a positive dose-response relationship between higher ethanol concentrations and increases in SDLP in both the simulator and on the test track (p<0.001 for both). In the simulator, this dose-response was evident already after 15min of driving. SDLP values were higher and showed a larger inter-individual variability in the simulator than on the test track. Most subjects displayed a similar relationship between BAC and SDLP in the simulator and on the test track; however, a few subjects showed striking dissimilarities, with very high SDLP values in the simulator. This may reflect the lack of perceived danger in the simulator, causing reckless driving in a few test subjects. Overall, the results suggest that SDLP in the driving simulator is a sensitive measure of ethanol impaired driving. The comparison with real driving implies relative external validity of the simulator.

Driving simulator sickness: impact on driving performance, influence of blood alcohol concentration, and effect of repeated simulator exposures

Simulator sickness is a major obstacle to the use of driving simulators for research, training and driver assessment purposes. The purpose of the present study was to investigate the possible influence of simulator sickness on driving performance measures such as standard deviation of lateral position (SDLP), and the effect of alcohol or repeated simulator exposure on the degree of simulator sickness. Twenty healthy male volunteers underwent three simulated driving trials of 1hs duration with a curvy rural road scenario, and rated their degree of simulator sickness after each trial. Subjects drove sober and with blood alcohol concentrations (BAC) of approx. 0.5g/L and 0.9g/L in a randomized order. Simulator sickness score (SSS) did not influence the primary outcome measure SDLP. Higher SSS significantly predicted lower average speed and frequency of steering wheel reversals. These effects seemed to be mitigated by alcohol. Higher BAC significantly predicted lower SSS, suggesting that alcohol inebriation alleviates simulator sickness. The negative relation between the number of previous exposures to the simulator and SSS was not statistically significant, but is consistent with habituation to the sickness-inducing effects, as shown in other studies. Overall, the results suggest no influence of simulator sickness on SDLP or several other driving performance measures. However, simulator sickness seems to cause test subjects to drive more carefully, with lower average speed and fewer steering wheel reversals, hampering the interpretation of these outcomes as measures of driving impairment and safety. BAC and repeated simulator exposures may act as confounding variables by influencing the degree of simulator sickness in experimental studies.

Evaluation of measures of impairment in real and simulated driving: results from a randomized, placebo-controlled study

ABSTRACT Objective: Standard deviation of lateral position (SDLP) is often the primary outcome in experimental studies on impaired driving. However, other measures may be easier and more practical to obtain and reflect a broader range of driving-related behaviors. We wanted to assess the validity and sensitivity of a range of measures in a driving simulator as well as during real driving and compare these to SDLP. Methods: Twenty healthy male volunteers undertook 6 driving trials each, 3 in a regular car on a closed track resembling rural road conditions and 3 in a simulator with an identical driving scenario. Ethanol was used as impairing substance due to its well-characterized effects on driving. The subjects were tested sober and at blood alcohol concentrations (BAC) of approximately 0.5 and 0.9 g/L. We explored dose–response relationships between BAC and a range of driving-related measures, as well as their BAC-dependent effect sizes. Results: In simulator driving, ethanol intake increased steering wheel reversal frequency, steering wheel movement measures, average speed, standard deviation of speed, and pedal use frequency. At the test track, only steering wheel movement and standard deviation of speed were significantly correlated to BAC. Likewise, reaction to unexpected incidents and observance of red traffic lights were adversely affected by ethanol in the simulator but not at the test track. Whereas SDLP showed a relatively large effect size that was similar in simulated and real driving, all other measures demonstrated smaller effect sizes, with less pronounced BAC effects on the test track than in the simulator. Conclusions: The results suggest that the driving-related measures explored in this study are less sensitive to alcohol-mediated driving impairment than SDLP, especially during real (test track) driving. The discrepancy in effect sizes between simulated and real driving may imply low external validity of these measures in simulator studies.

An Experiment on the Effectiveness of Remote, Robotic Inspection Compared to Manned

This paper evaluates the effectiveness of remote inspections using a robot in a laboratory experiment. The experiment differs from most human-robot interaction experiments in its direct comparison of manned and robotic operations. 21 participants each performed three manned inspections and three inspections with each of the two remote inspection methods, teleoperated and assisted. The effectiveness was measured based on the number of errors they were able to identify. Teleoperated inspections were found to be less effective than manned, although this difference was not statistical significant. Assisted inspections, implemented as an interactive simulation prototype representing a robot with higher autonomy, had similar effectiveness as manned. Because of the time and high cost required for manned inspections of offshore wind turbines, remote inspection can give a large economic benefit. However, this will only be a viable alternative if the robot system is inexpensive and remote inspections are as effective for identifying errors as manned inspections, which the experiment presented here suggests.

Digging Deep: The Effect of Design on the Social Behavior and Attitudes of People Working in Underground Workplaces in Europe

With the cities of the world grappling with the ever-increasing challenge of land scarcity, sustainable solutions such as Underground Workplaces (UW) have been getting renewed interest. However, considering the hefty investments that will go into building UW and since the success of this solution relies on the wellbeing of the people who are to occupy it, there is a need to examine existing UW from a human factor point of view. In this paper, we present an analysis of how design factors in UW affect the attitudes and social behavior of employees and how these perceptions and attitudes towards the workplace vary across different work types. According to our analysis organic elements, art, architecture and lighting affect social behavior and attitudes. These factors can be manipulated according to the type of work and environment in a way that is in line with company values. The paper also attempts to create a framework for how the significance of the work environment varies with the type of work and workplaces.