Driving skills retention of young drivers after period of driving inactivity

• Main Author: Upahita, Dwi Phalita
• Other Authors: Lum Kit Meng
• Format: Theses and Dissertations
• Language: English
• Published: 2018
• Subjects: DRNTU::Engineering::Civil engineering::Transportation
• Online Access: http://hdl.handle.net/10356/73914
• Institution: Nanyang Technological University

Overall on-road driving skill is a cumulated acquisition of driving skills learned during the training period and furthered tempered with post-licensing driving exposure on the roads. Training serves to develop a person’s basic driving skills to survive safely on the roads at first, while subsequent on-road driving hones the driving skills further. Inactivity from on-road driving can result in deterioration of the driving skills. Particularly for the case of inactivity immediately following licensure, which is not uncommon in Singapore, the learned skills can degrade rapidly. This research addresses the issue on skills degradation of learned driving skills as a result of driving inactivity, specifically for young-inexperienced drivers. This study is divided into two stages: passive mode and active mode. The first stage, passive mode driving assessment served as the preliminary stage to examine the effect of training, driving experience and inactivity using a simple task. A series of experiments were conducted on a driving simulator for different subject groups involving active, inactive (ever since licensure), and no licence subjects. The participants watched a video of driving along a road that contains several types of hazard and were instructed to initiate a braking response every time they detect a hazard. The response latency between onset of hazard till the response was registered is used as the performance indicator. The hazards (stimuli) are characterised in terms of collision damage potential, including personal injury, and collision avoidance potential. The results indicate that training and inactivity (lack of experience) affect the hazard identification strategy and perception towards risk. However, the passive driving simulation mode setting comes with limitations. It is not able to replicate the complexity of the driving task (i.e. no vehicle control required) and only limited data can be obtained. Therefore, an active mode driving assessment was conducted in the second stage. For the second stage involving active mode driving assessment, a series of experiments were conducted on a driving simulator for different subject groups involving active driver, novice driver (freshly licensed driver), inactive driver (never ever drive upon licensure), and no licence subjects. In the second stage, the participants were given a full control over the vehicle. The experiment was divided into two parts: vehicle handling performance, and hazard perception and anticipation. For the first part, the participants drove through a stretch of expressway under free-flow conditions, and lane positioning control was monitored. It is found that without on-road driving exposure, driving skills like maintenance of lane positioning control in terms of lane wandering and lane encroachment may deteriorate after some periods of inactivity. The deterioration varies at a different rate, with faster deterioration for more complex tasks. In complex driving tasks, the skills level can regress close to untrained level. The second part of the active driving assessment is a hazard perception and anticipation test. This part was modified from a conventional hazard perception test. In this experiment, instead of watching hazard contained in a video, the participants drove a car along a specified route in which several hazards had been planted. An eye tracker was used in this experiment to examine the eye behaviour when participant identifies the hazards. Response latency was further refined into three sub-components: lag time (LT), time-to-fixation (TF) and PIEV (Perception-Intellection-Emotion-Volition) time. The results show that driving experience gives a dominant effect in improving the ability to respond to hazardous situations. Meanwhile, inactivity not only prevents the drivers to gain more experiences and improve their skills but also can cause deterioration of their driving skills. The overall results show that training builds up the level of competency in driving. It also demonstrates that inactivity from driving, especially for young recently-licensed drivers, can affect their driving performance as well as their perception of risk. The results indicate that without any on-road exposure, some driving skills, i.e. lane wandering control and lane encroachment control, may deteriorate after some periods of inactivity. The deterioration may vary for different set of skills, with more complex (e.g. lane encroachment control) tasks having faster deterioration rate. For more complex driving skills, the deterioration can result in the level of competency being relegated close to untrained level. The deterioration of driving skills is especially more sensitive for young-inexperienced driving licence holders, as the skills that they have gained may not be ‘deeply rooted’ yet. The results also suggest that post-licensing driving exposure is needed not only to retain but also to improve the lateral control skills. With regular practice, the skills can be strongly retained and lasted longer as well. Exposure to real road driving experience also helps to familiarise with road conditions and thus further improves and enhances the driving skills. Hereby, authorities may consider a mandatory refresher course for driving licence holders who have been inactive for a long-term period, especially for young licenced subjects who have ever ever progressed to on-road driving. It will help the drivers to refresh the skills that they have learned during licensure as well as familiarise them to the real road situations. It is to make sure that the drivers will be at least be back to the skill level when they passed the driving licence test.