How Mobile Phone Use Influences Driving Ability In today’s technological world, it is rare to find someone without a handphone, especially in developed societies. It is also in these societies where it is common to drive a car. The concurrent use of these machines has resulted in many car accidents, injuries and even death (Kunkle, 2017). Therefore, it is important to investigate the aspects of phone usage that result in these accidents. Phone usage could influence driving ability as previous research has shown that extra visual processing can decrease one’s attentional resource (Handy, Solitani, & Mangun, 2001, as cited in Patten, Kircher, Östlund, & Nilsson, 2004). Another research showed that the use of cell phones increased the risk of a car accident by four times (Redelmeier and Tibshirani, 1997, as cited in Consiglio, Driscoll, Witte, & Berg, 2003). According to the Wickens multiple resource theory (Wickens, 1992, as cited in Lamble, Kauranen, Laakso, & Summala, 1999), there is minimal interference when using a hands-free phone while driving as different cognitive resources are used – verbal-auditory and visual-spatial – and thus, there would be minimal influence on driving ability. Conversely, there is great interference when using a hand-held phone while driving as the same visual-spatial cognitive resource is used, which would negatively influence driving ability. However, according to Kahneman’s capacity model, there is limited attentional resource that is divided when a driver engages in secondary activities (Kahneman, 1973). This means the use of both hand-held and hands-free phone would negatively influence driving ability. Previous research indicates the possibility of phone use having a negative influence on driving ability. In addition, Kahneman’s capacity model provides strong support for the negative influence of phone use on driving ability. However, it is not yet known whether different task demands, and which type of phone tasks have a negative influence on driving ability. Therefore, based on Wickens theory, the hypothesis is that only mobile phone tasks that utilise the visual-spatial resource will have a negative influence on driving ability. In addition, based on Kahneman’s theory, the hypothesis is that the higher the amount of attentional resources used, the greater the negative influence on driving ability. This literature review aims to answer the question on how mobile phone use influences driving ability. This paper will first address the influence of the type of distraction on driving ability. The second part will focus on the influence of the degree of distraction on driving. Investigating the influence of the type of distraction helps to clarify which secondary tasks influence driving ability. It is not yet known whether both physical manipulation and mental use of the phone, or just one of it, influences driving ability. Next, investigating the influence of the degree of distraction enables understanding of how task demands influence driving ability. Currently, it is not clear whether varying levels of task demands have the same influence on driving ability. Thus, the paper first establishes the types of tasks that influence driving ability, and later proceeds deeper, into understanding the influence of different amounts of resources required by the tasks. The Influence of the Type of Distraction on Driving Ability Previous research has shown that the chances of an accident occurring increases when a cell phone is used while driving (Redelmeier and Tibshirani, 1997, as cited in Consiglio et al., 2003). However, it is not clear whether all kinds of cell phone usage have the same influence on driving. Based on the multiple resource theory, distractors that utilise the same cognitive resource as driving will decrease driving ability. The hypothesis is that only mobile phone tasks that utilise the visual-spatial resource will have a negative influence on driving ability. This section explores the influence of the type of distraction on driving ability. Lamble et al. (1999) studied the influence of the type of distraction on driving ability. In this study, there were 19 participants, nine females and ten males, aged 20 to 29 from the University of Helsinki and the Helsinki Unemployment Center. A keypad was placed on the dashboard, on the right side of the steering wheel, and the experiment was conducted on a 30km road. The experiment participants drove 50 metres behind the researcher’s car, stepping on the brake pedal when noticing the researcher’s deceleration. Each participant went through all three conditions and each condition had ten consecutive trials. The order always started with the control task, followed by the cognitive task and the phone dialling task – the order of the two conditions were counterbalanced. The sequence was done three times. In all conditions, participants paid attention to the car ahead. For the phone dialling condition, participants typed in sets of three numbers, said by a researcher, into the keypad. The next set was said once the previous had been typed, till the participant braked. For the cognitive task, the researcher said one number and the participant gave two numbers. The researcher said the next number once the last had been said, till the participant braked. The researcher’s car decelerated when at 80km/h. Driving ability was measured by the brake-reaction-time (BRT) – the longer the reaction time, the worse the driving ability. The results showed that both the phone dialling and cognitive condition had a longer BRT than the control. This study showed that both types of distractions have a negative influence on driving ability. In this study, the influence of the types of distractions on driving ability was not well measured due to poor operationalisation of hand-held and hands-free phone use while driving. When drivers key in numbers to make phone calls, they do not always do it in triplets, and they must recall the numbers themselves. For the cognitive condition, the mental stimulation is not equivalent to the mental processes of having a conversation on a hands-free phone. Thus, both operationalisations were not accurate simulations. It is important to operationalise the constructs well, as the result is not useful if it is not an accurate reflection of the effects in real life. The next study operationalises the types of distractions better, by using the actual distractions. Consiglio et al. (2003) studied the influence of the type of distraction on driving ability. There were 22 participants, 11 women and 11 men, aged 18 to 27 from Miami University. There was an apparatus to simulate driving, and a red lamp, five centimetres in diameter, was placed two metres away from the participant’s eyes. Participants released the accelerator pedal and pressed the brake pedal when the red lamp lit up. The reaction time was measured as the difference in time between the lamp activation and the initial movement of the foot, in milliseconds. Each participant did all five conditions with five trials for each condition. The five trials for each condition were done consecutively and the order of the conditions were counterbalanced. In all conditions, participants kept their eyes on the red lamp. In the control condition, participants only paid attention to the lamp and in the radio condition participants listened to radio music. For the passenger condition, participants had a simulated relaxed conversation with a researcher playing the role of a passenger. In the hand-held condition, participants talked to the same researcher through a hand-held phone. In the hands-free condition, participants talked to the same researcher through a hands-free phone. Driving ability was measured by the brake reaction time – the longer the reaction time, the worse the driving ability. The results showed that the reaction time in both phone conditions and the passenger condition was longer than the control and radio condition. This study showed that conversations over hands-free and hand-held phones, and in person have a negative effect on driving ability. It can be concluded that all types of distractions have a negative influence on driving ability. In the first study, this influence was shown in the increase in BRT due to both physical manipulation and mental processing. The second study showed this negative influence in the increase in reaction time when using a phone and having a conversation in person. Thus, it can be concluded that the type of distraction does not explain the negative influence on driving ability. Therefore, the hypothesis that only mobile phone tasks that utilise the visual-spatial resource will have a negative influence on driving ability is not confirmed. This section showed that the type of distraction does not explain the negative influence on driving ability. The reason for this could be, that any secondary task requiring the driver’s attention, reduces the focus on driving and leads to a decrease in driving ability. This reasoning is in line with the second hypothesis that the greater amount of attention required by the distraction, the greater the negative influence on driving ability. Thus, the next section addresses the alternative explanation for how the use of mobile phones influence driving performance by looking at the extent of usage. Conclusions and Discussion It can be concluded that mobile phone use, requiring large attentional resources, has a negative influence on driving ability. The first sub-section showed that all types of phone use have a negative influence on driving ability. The second sub-section showed that the greater the degree of distraction, the greater the negative influence on driving ability. Based on previous research that phone use increases the likelihood of accidents (Redelmeier and Tibshirani, 1997, as cited in Consiglio, Driscoll, Witte, & Berg, 2003), and the multiple resource theory of different modality-based resources, the hypothesis that only mobile phone tasks utilising the visual-spatial resource will have a negative influence on driving ability was formulated. This hypothesis is not confirmed as the first sub-section showed that tasks utilising the verbal-auditory resource also has a negative influence on driving ability. This inadequacy in explaining the influence of mobile use may be because physically manipulating the phone requires additional cognitive resources that is needed for driving. Therefore, based on the capacity theory, and previous research on distractions decreasing our attentional capacity (Handy, Solitani, & Mangun, 2001, as cited in Patten, Kircher, Östlund, & Nilsson, 2004), the hypothesis that the higher the amount of attentional resources used, the greater the negative influence on driving ability was formulated. This hypothesis was confirmed by the second sub-section which showed that the higher amount of attention required by the task, the greater the negative influence on driving ability. The conclusions are valid only till a small extent as all four studies are not representative of reality. The studies by Strayer and Johnston, and Consiglio et al. were conducted in a laboratory setting with a driving simulation which may not be representative, especially for the study by Strayer and Johnston as the tracking game using a joystick has little resemblance to driving. For the study by Consiglio et al., there are other cues to slow down, besides the red brake light of the car ahead and, drivers do not usually stare at brake lights. While the studies by Lamble et al. and Patten et al. better represent driving, the study by Lamble et al. simulated hands-free phone use through number generation and the study by Patten et al. simulated phone conversations through parroting numbers and number addition. These operationalisations may not use the same amount of cognitive load as conversations, and it is unlikely for drivers to generate, repeat or add numbers while driving. As such, it is unclear how accurate the results of these studies are, and the true extent of the negative influence of mobile phone use on driving ability. Thus, another study should be conducted where participants drive on roads and have real phone conversations. Next, the studies lack relevance in today’s digital age where most phones can be used hands-free, so there is little relevance in investigating the use of hand-held phones. Furthermore, the use of social media applications such as Facebook is not represented in any of these studies. It is important to gain deeper insight into this as there is a possibility that simply receiving a notification from one of the applications could be a great distraction to the driver, having a negative influence on driving ability. This can be investigated by conducting another study on the way current technological abilities of mobile phones influence driving ability. This literature review shows that mobile phone use has a negative influence on driving ability when a large amount of attentional resource is required. This implies that it does not matter how the phone is use but instead, the moment the driver’s attention is heavily occupied by a secondary task, it could put the driver and the passengers at risk of an accident. Therefore, distractions such as flashy billboards, and radio broadcastings should also be carefully considered before being posted.