Driving Task Research Articles

Interactive Effects of Sleep Deprivation, Time of Day, and Driving Experience on a Driving Task

Performance decrements after more than 24 hours of sleep deprivation (SD) are not only a monotonic function of the duration of SD, but are the result of an interaction between SD and time of day. The major deteriorations in performance during SD are still evident throughout the night, as in the non-sleep-deprived state. Twelve experienced and 12 inexperienced drivers drove a driving simulator for 20 minutes at 0800, 1100, 1400, 1700, and 2000 hours on two testing days. One testing day was conducted after a normal night's sleep, and the other after one night of SD. Reaction time (RT) was also measured while driving. The standard deviation of both lateral position and speed were significantly higher during SD. Performance steadily improved across the day between 0800 and 2000 hours, and the absence of any sleep-by-time interactions suggests that the rhythm of driving performance across the day was similar after both normal sleep and SD. Inexperienced drivers had higher RTs than experienced drivers in both sleep-deprived and non-sleep-deprived conditions. These results have important implications for those involved in the transport industry.

Time-To-Collision: A Sensitive Measure of Driver Interaction with Traffic in a Simulated Driving Task

In the future, on-board driver monitoring systems could use time-to-collision (TTC) metric algorithms as a real-time measure of driving performance, and alert the driver if performance falls below minimum performance criteria. Such monitoring systems remain years away, but it is currently possible to measure TTC in a simulator. This paper discusses a study to determine whether TTC varies as a function of driver impairment in a simulated driving task. Alcohol was administered to eleven participants, and TTC measures were obtained at 0.00%, 0.04% and 0.08% blood alcohol concentrations (BAC). The results support use of the median TTC, which varied as a function of BAC, as a measure of in-traffic maneuvering performance.

Time-to-Collision Estimation in a Simulated Driving Task

Three experiments are reported that examine the role of visual information in the estimation of time to collision. Participants were shown video clips taken from within a car as it approached a stationary target. In the first two experiments the videos were occluded either at a constant time before collision or at a constant distance from the collision. Approach velocity and viewing time were also manipulated. The third experiment again varied approach velocity but did not occlude the video prior to collision with the target. In all three experiments the participants were required to press a pedal when they estimated that collision occurred. Results from all experiments indicated that approach velocity had the greatest influence on the accuracy of collision estimation, and accuracy improved with increasing velocity. Varying viewing time from 1 to 8 s had little effect on estimation accuracy. These results emphasize the role of global optic flow rate in the judgment of time of collision.

Simulated Driving Task Using Tracking Method

Simulated Driving Task Using Tracking Method

The Effects of Age and Target Location Uncertainty on Decision Making in a Simulated Driving Task

Spatial localization has been identified as an age-sensitive process in selective attention. Because visual search in driving involves uncertainty concerning the location of information necessary for maneuvering decisions, an experiment was conducted to examine the effects of age and target location uncertainty on a simulated driving task. Seventeen younger subjects (aged 30 to 45 years) and 13 older subjects (aged 65 to 75 years) completed three tasks including two reaction-time tasks and a simulated driving task. The reaction-time tasks included three conditions (simple left, simple right, and two-choice) in a laboratory and in a stationary vehicle. The simulated driving task was conducted on a closed driving course while subjects sat in a stationary vehicle. Subjects were required to select one of two lanes using information presented either on a changeable-message sign or on traffic signals. In the high-certainty condition, subjects were told where to look for relevant information; in the low-certainty condition, they were told that information could appear in either place. Response times were measured from sign or traffic signal onset to the subject's activation of the vehicle turn signal. The results indicated small, non-significant differences between age groups for the reaction-time tasks. Significant age-related differences were found in the simulated lane-selection task. Older subjects were 15% slower overall than the younger subjects. Uncertainty concerning the location of relevant information slowed decision-making speed for all subjects, but proportionately more for the older subjects (16% versus 11% for the younger age group). Uncertainty slowed responses to the changeable message sign more than to traffic signals for subjects in both age groups. The results are consistent with the spatial localization hypothesis, and suggest that older drivers may have more difficulty than younger drivers locating targets in visual search while driving. The results also suggest that effective use of changeable-message signs requires placement in locations with high expectancy, and allowing drivers sufficient time to locate the sign before reading the scrolling message.

Age differences in divided attention in a simulated driving task.

The ability of young, middle-aged, and old adults to divide attention was examined using a dual task experiment involving two continuous performance tasks. The first task was a compensatory tracking task modeled after the important everyday activity of car driving. The second task was a self-paced visual choice-reaction time task requiring analysis of a small visual display presented in such a way that no eye movements were required when the two tasks had to be performed simultaneously. Single-task difficulty was individually adjusted for each subject. Performance-Operating-Characteristics were used to control for individual differences in attention allocation strategies. Even when individual differences in single task performance were adequately controlled for, elderly adults showed a significantly decreased ability to divide attention when compared with young and middle-aged adults. Young and middle-aged adults did not differ in the ability to divide attention.

Review of Relationships Between Steering Wheel Reversal Rate and Driving Task Demand

Previous literature and some new data on the relationship between steering wheel reversal rate (SRR) and driving task demand are discussed in terms of a set of theoretical assumptions proposed by Macdonald and Hoffmann (1978). SRR is generally expected to increase with increasing task demand; however, several recent studies found a significant decrease in SRR. It is argued that whether the relationship is positive or negative depends on the level of task difficulty relative to the driver's capacity to cope with it.

Relationship between Predicted Stress and Measured Attentional Demand in a Simulated Driving Task

The need exists for a method whereby a highway designer can determine, during the design stage, whether a highway design will demand so much of a driver's attention that he is left with insufficient time to look for and avoid accidents. Several methods exist for predicting how busy a subject will be under given circumstances. However, no direct comparisons between predicted stress and measured percent occupied have been attempted. In order to determine this relationship, various levels of difficulty of a tracking task and of a word-reading task were presented to 15 subjects. The stress for each difficulty level was predicted and attentional demand was measured directly. The relationship between predicted stress and percent occupied was found not to agree with the relationship commonly assumed in the literature on workload.

Effects of experience of the driver on heart-rate, respiration-rate, and subsidiary reaction time in a three hours continuous driving task.

From accident statistics a difference was hypothesized between experienced and inexperienced drivers in vulnerability to continuous driving. This difference was used as a basis for a comparison of changes in autonomic measures and reaction time over driving time. The result showed significant effects of experience on both types of measures. Heart-rate pointed to experienced and reaction time pointed to inexperienced drivers as being the most vulnerable to continuous driving. This contradiction was solved with reference to statistical data and validation of the reaction time task. Thus in this study reaction time was preferred to the autonomic measures

Effects of operator mood on performance in a simulated driving task.

175 males and 175 females were administered a Mood Adjective Check List and were then tested in a simulated driving task. Correlations between mood factor scores and performance measures were computed. Little relationship appeared between mood factors and performance on the various tasks required in the operation of the device. However, in an analysis involving high and low mood-score groups for each mood factor, Ss scoring high on factors of aggression, anxiety, and fatigue performed more poorly on various tasks than Ss who scored lower on these factors. Also, performance of males was superior to that of the females on several tasks.

A DEVELOPMENT OF A CONCEPTUAL FRAMEWORK OF THE DRIVING TASK.

A conceptual framework is developed based on observations of driving behavior under actual traffic conditions. After the framework has been established, the assumptions and implications are contrasted with those in the theories of traffic flow that relegate the driver's contribution to a minor role. It would appear that theorists are mainly concerned with traffic flow and safety while each driver is more concerned with independence and constancy of his vehicle's movement.