Driving simulator-based training to improve self-rating ability of driving performance in older adults – a pilot study

Maintaining safe and independent transportation mobility is important for all persons, and even more so for older adults. Older drivers may choose to restrict their driving due to a lack of confidence or lack of alternative transportation options, but for many older adults, driving is seen as the primary mode of transportation [1, 2]. However, declining abilities due to normal ageing are not always compensated by the cars, driving environments, or driving behaviours [3‐5].

When controlling for mileage, older drivers are not in general overrepresented in accident statistics, according to previous research [6]. However, as a part of the total population of Sweden, older drivers are over-represented among fatal injuries on the road. During 2014–2016, older drivers represented 32% of fatalities (STRADA data), while they represented 20% of the population [7]. Several factors can explain this over-representation such as the lower level of violence of the collision needed to injure or kill an older driver than younger people. Most older drivers tend to self-regulate their driving correctly; i.e., limiting their exposure to challenging situations such as avoiding driving at night, in the rain, or during rush hour [8, 9]. However, not all older drivers are able to self-regulate their driving behaviour [10]. Self-regulation alone is therefore not sufficient to ensure safe driving among older drivers.

Awareness and insight into one’s own driving abilities can determine the choices one makes [11]. The interactions between self-monitoring, beliefs about driving, and factors supporting driving abilities enable and influence safe driving behaviour [11]. However, it is unknown if older drivers have insight into their own driving abilities or whether external factors and changes in lifestyles result in self-regulation [4, 5]. It is often said that older drivers adjust their driving behaviour and habits to their age-related changes [5]. The reason may be that they restrict their driving due to awareness of specific impairments such as physical or visual abilities [12, 13]. However, not all drivers are capable of adjusting their driving due to declines in cognitive abilities, medications taken, and the aging process itself [11, 13, 14]. The key question is to balance task demand and capability; i.e., calibration [15].

Results from previous studies of self-regulation vary as to what extent older drivers restrict their driving or what type of self-regulation they apply [4, 16, 17]. Most studies have simply asked older drivers if they modify their driving. Drivers with a lack of insight are less likely to self-regulate and may overestimate their driving ability [16, 18]. It is a challenge to estimate safe driving correctly, both objectively and by the drivers themselves. Some drivers over-rate their driving ability, while others under-rate it, and some drivers make correct estimations [19]. People who over-rate their ability are more likely to be risky drivers, not only for themselves but also for others using the road [20]. These drivers might turn up in crash statistics, but usually there is no one single cause of an accident. Those who under-rate their ability are probably more reluctant to drive and might be more difficult to identify unless one is searching for drivers who have given up driving. Several attempts have been made to find a realistic way to classify drivers in to correct, under-, and over-raters of their own ability [21, 22]. However, a general principle has been to compare a person’s self-assessment with some more or less objective measure of ability [19, 22].

As crashes and near crashes are relatively rare, we usually have to rely on driving behaviour data such as time-based safety margins like Time-To-Collision (TTC) as well as expert judgement based on observations of behaviour [21]. Educational interventions, such as updated knowledge on traffic laws or other strategies such as transmission type, may help to ensure the competency of older drivers [14]. Another alternative strategy is to encourage and raise awareness among older drivers to self-rate their driving skills and compare this rating with that of an independent assessor, and thereby be able to modify and adjust one’s driving appropriately [20, 23]. Thus, as some older drivers tend to overate their own driving abilities [20, 21], there is a need to investigate drivers’ insight and to be able to utilize more objective measures. The purpose of the present study was to investigate the potential of using simulator-based training (SBT) to improve older drivers’ self-rated driving ability. The hypothesis was that SBT could contribute to improving people’s self-rated performance. Moreover, providing feedback, both corrective (errors made) and rewarding (correct behaviour) feedback, may result in driving modifications.

The study was designed to study the possibility of training for self-rated driving ability in a simulator, and the impact of corrective feedback versus corrective and rewarding feedback during training.

The results were based on the two feedback-groups; 11 participants (7 men and 4 women) received corrective feedback, and 10 participants (7 men and 3 women) received corrective and rewarding feedback.

In this study, the objective was to investigate the potential of using simulator-based training to improve older adults’ self-rated driving ability. The drivers’ average deviation from the expert assessment decreased after training, with those participants who deviated the most initially improving substantially. All drivers with a difference more than − 0.7 showed positive changes (i.e. their ratings came closer to being “correct” in their estimation). This shows the potential of a simulator training programme in helping people to better calibrate their driving abilities.

At the first training session, all participants underestimated their performance. This may be due to their lack of acquaintance with simulator driving, since none of them had used a simulator and older drivers seldom play videogames. As a group, they changed their performance from under-rating to over-rating, but their self-rating became closer to the expert’s rating. This may suggest that this form of training may be more relevant for persons who under-rate their abilities than for those who over-rate their abilities (i.e., the training made them perceive themselves in a more positive and correct way).

Providing feedback is a concept that has been used in previous studies to improve performance and provide insight of one’s own behaviour [25]. A simulator setting offers an opportunity to let drivers experience situations where both overrating and underrating might manifest itself in different behaviours; e.g., making a left turn at an intersection with either too short of a time gap or being too hesitant. Feedback can be an effective means to both improve performance and provide insight into one’s own behaviour. Thus, to help the drivers to a better self-rating, we used both corrective and rewarding feedback during the training. Only the group with rewarding feedback reduced their penalty points despite an escalating degree of difficulties. They did not, however, asses their performance better than the other group.

Rewarding feedback may be more relevant to under-raters but negative to over-raters. The results suggest that training, rather than rewarding feedback, does more to improve accurate self-rating. In order to change under- or over-raters’ assessments, attitudes towards training must change, suggesting that training gives one self-confidence and a better self-rating. Rewarding feedback, on the other hand, gives them a better performance that may convince them that they will drive safer after the training. Many women stop driving too early, possibly due to degraded confidence [2]. Training in a simulator might help them improve their self-rating and, with rewarding feedback, also attain better performance. How to address the person who over-rates themselves might be better achieved by other type of feedback. This needs to be further investigated [26].

Driving is a cognitively demanding task [13, 27] and some older drivers have insight into their abilities and might compensate and change their driving behaviour. However, not all have insight into their declining skills and are not able to adapt their driving behaviour [11]. Even if the deviant self-assessment could be seen as a personal trait that persists into growing older, we might see other causes for an incorrect self-assessment, such as lack of understanding age-related functional declines. Ageism is also a factor that can promote a driving style that is subjectively viewed as very competent (e.g. to choose a higher speed) [28]. General (prejudicial) attitudes in society of older drivers as risky drivers might also contribute to an unrealistic degraded self-assessment. We can see ourselves as both higher and lower performers compared to what we actually are. Defensive driving, often promoted for older drivers, can have side effects such as unrealistic beliefs of being able to master critical situations or loss of self-confidence. Those drivers who do lose confidence in difficult driving situations tend to avoid those situations when possible [16].

SBT has previously focused on technology, but much remains on educational and didactic issues [29]. Questions such as: “How should the training be designed?”, “How much and for how long?”, “Should feedback be used and how?”, “Direct augmented feedback?”, or “Can several sense modalities enforce impact?”. In summary, SBT can be used to improve older drivers’ ability to assess their own performance, and feedback plays an important role, but should be further investigated. A limitation with the current study is that it did not include a control group. Thus, we cannot rule out the influence of extraneous factors as the actual cause of the observed change. However, as the study was a before/after study the participants serves as their own controls. Furthermore, the main purpose was to investigate improvements in self-assessment not the actual driving performance per se and the drivers did not get any feedback on their assessment, i.e., how they compared to expert assessment only on their performance. The difficulty of the lessons increased for each session and thus, assessment could be more difficult. In summary, a change from being less confident to over confident and specifically closer to the expert assessment could be seen as a real improvement even if it needs to be further investigated by the inclusion of a control group. Moreover, simulator sickness, as observed in this study, might hamper the use of simulators, specifically with older drivers, and further work is needed to decrease this problem. A high proportion of our participants could not continue due to simulator sickness, although a driving simulator appears to be a safe and cost-effective method for assessing driving performance. Several studies have reported similar results and also showed a significant difference between older and younger adults [30]. A problem with the simulator, which may increase simulator sickness, was that many of the participants experienced difficulties with manoeuvring (i.e., the steering wheel) and thought it was too “sensitive”. This is a limitation and needs to be examined and adjusted. Another important observation made by the test leader was the participants speed adaptation during the first training. They were all inexperienced with simulator driving, which made them drive very slowly, and might have caused fewer driving errors.

Being able to rate your own performance can be vital for maintaining the safe mobility of older drivers. Incorrect self-rating can lead to an increased risk of being involved in a crash or unjustifiable restriction in mobility. SBT showed positive training effects on the ability to self-rate one’s driving ability, and rewarding feedback contributed to less penalty scores. However, simulator sickness is a shortcoming that needs to be addressed, and the optimal form of feedback should be further investigated.