I. D. Brown

Risk perception and decision taking during the transition between novice and experienced driver status

Abstract Young drivers are statistically overrepresented in road accidents. Their elevated risk is a complex function of chronological age and driving experience, both of which are associated with acceptance and misperception of risk on the road. A better understanding of the cognitive changes which accompany their transition from novice to experienced driver status should allow us to elucidate the factors underlying their acceptance and misperception of traffic risk. With, such an understanding, we would be in a better position to take decisions about improving their safety via training and education schemes rather than via legislative constraints on their exposure to risk. This paper considers evidence that young drivers underestimate certain traffic hazards and overestimate their own driving abilities. The potential contribution of these misperceptions to their faulty decision taking during skills acquisition is discussed in the light of recent findings from relevant research. Some implications for fut...

MEASURING THE SPARE ‘MENTAL CAPACITY ’OF CAR DRIVERS BY A SUBSIDIARY TASK

It is impossible to determine the degree to which a driver is absorbed in his driving by measuring his overt responses directly. However, relatively small changes in his spare ‘ mental capacity ’ can be detected by scoring his performance on a subsidiary task, which has no adverse effect upon driving. This technique is sufficiently sensitive to reveal the higher level of concentration required in a shopping area as compared with that required in a residential area

Components of driving skill: experience does not mean expertise

Using an instrumented car driven in normal traffic, we assessed the driving skills of trained experts, of normal, experienced drivers, and of novices. Previous research suggests a fairly simple picture of improvement in driving skills with experience, and for aspects of car control (e.g., steering path, speed of manoeuvres) our results confirm this: normals largely resembled experts, while novices performed more poorly. There are reasons to suspect, however, that experience may not always be so beneficial. For example, one important variable may be feedback, or information indicating to the driver that a particular action is or is not important in terms of overall goals (progress, safety, etc.). Where feedback is good, simple experience may bring expertise, but where feedback is poor, skills may fail to improve or even deteriorate once explicit tuition is removed. Correspondingly, our findings showed that for scanning patterns (e.g., mirror checking), anticipation (e.g., braking into an intersection), and...

Prospects for technological countermeasures against driver fatigue

There are three reasons for giving serious consideration to technological countermeasures against driver fatigue: 1, fatigue is a persistent occupational hazard for professional drivers; 2, some professional drivers are under considerable pressure to reach their scheduled destination, in spite of feeling drowsy; 3, fatigue adversely affects an individuals ability to assess their own fitness to continue driving. However, there are two reasons for exercising caution in implementing technological countermeasures: 1, their reliability under real traffic conditions is largely unproven; 2, they could be used by unscrupulous drivers to support the continuation of journeys that should have been terminated because of human impairment. This paper draws on the findings of research into the origins, symptoms and development of human fatigue, and on recent research into driver-support systems, to assess the prospects for implementations of technological countermeasures against driver fatigue in the foreseeable future.

Measurement of control skills, vigilance, and performance on a subsidiary task during 12 hours of car driving.

Eight subjects were given short driving tests at 0700, 1000, 1300, 1400. 1700 and 2000 hours on 2 days: (1) under experimental conditions of continuous driving and (2) under control conditions in which they carried on with their normal work between tests. Car control skills and performance on a subsidiary task of time-interval production were measured on a 2·2 mile test circuit in city traffic. Pulse rate and oral temperature were also recorded. Vigilance was measured during main-road driving on the experimental day by scoring time taken to respond to a light signal. Vigilance improved significantly during the spell of prolonged driving. Time-interval production was reliably more variable under experimental conditions than under control, but this difference was independent of the duration of the driving period. Differences in car-control skills between conditions were slight and statistically unreliable. These results support previous findings that a virtually continuous 12 hour period of driving during t...

Cognitive abilities and safety on the road: A re-examination of individual differences in dichotic listening and search for embedded figures.

Five cognitive ability tests were administered to a sample of 153 bus-driver trainees. The embedded figures test (EFT) of Witkin (1950) and the dichotic listening test (DLT) of Gopher and Kahneman (1971) were chosen on the basis of previously reported correlations with driving accident rate. The remainder were designed to cast light on what cognitive processes the EFT and DLT measure, and hence why they should relate to driving ability. The EFT correlated only marginally with success in driver training and with accident rate in a follow-up period of two years. There was no support for the hypothesis that this test measures a general ability to resist the influence of dominant stimuli. Instead a substantial correlation (0·64) was obtained with a typical ‘intelligence’ test. The DLT showed no correlations with driver performance measures, thus failing to replicate earlier findings. There was no support for the hypothesis that this test measures a general ability to switch from one task or mental set to anot...

A comparison of two subsidiary tasks used to measure fatigue in car drivers

Abstract Car driving has been studied by combining it with a subsidiary task, performance on which is negatively correlated with the perceptual load imposed by changing conditions of traffic. The present experiment compares a subsidiary task which required almost continuous attention to an auditory display, and which involved memory spans of only 3 sec, with an alternative task which did not require continuous attention, but which involved memory spans of up to 55 sec. The former was found to have some advantages. This comparison was combined with a study of men engaged in 8-hour spells of car driving. Some explanations are offered for the finding that performance on the subsidiary tasks was better at the end of the work-spell than at the beginning.

Drivers' judgments of safe distances in vehicle following.

Driver behavior in the vehicle-following situation, a major source of road accidents, was investigated using a controlled-track experiment. Drivers were found to adopt headways of approximately 2 s irrespective of speed of travel, driving experience, or instructed probability of the leading vehicles stopping. Under the optimal conditions used, drivers demonstrated that such headways were more than adequate to avoid tail-end collisions in an emergency situation. The implications of these results for the development of perceptual-motor support devices and the attribution of causes in road accidents are discussed.

EFFECT OF A CAR RADIO ON DRIVING IN TRAFFIC

Abstract Eight drivers were tested in light and heavy traffic while listening to recorded programmes of music and speech. The effects of these auditory distractions on the use of the car controls and time taken over a standard test circuit of 2·2 miles were measured by comparison with scores obtained in a quiet condition of normal driving. In light traffic, music significantly reduced the frequency with which the accelerator and brake pedals were used (p = 0·05), and in heavy traffic it increased the time taken per circuit )p < 0·05). These changes were interpreted as being beneficial. Speech had an insignificant effect on all scores, whether listening was motivated simply by interest in the programme, or by the need to remember its content.

Dual Task Methods of Assessing Work-load

Abstract Various applications and design factors of dual task situations are critically surveyed. It is concluded that many applications make questionable assumptions and that many frequently used features of design are unsatisfactory. However, the technique appears to be valid and useful for the study of individual differences in processing resources, when the additional task is secondary, presents discrete stimuli which impose constant load, is carried out at a forced pace and competes with the primary task for processing resources only.