Driver Distraction

Driver Distraction


  • This review sought to summarise the key findings from literature in the domain of driver distraction. With the proliferation of mobile communications and in-vehicle technologies in recent times, the use of technology while driving has developed to be of primary interest within this domain. As such, there is a deliberate focus towards the distracting effects of technology throughout the review.

  • Distraction is considered to be a major risk factor in driving incidents. However, the exact extent of driver distraction as causal factor in accident rates can be difficult to measure due to variations in definitions of driver distraction and data collection methods (Stevens & Minton, 2001; Beanland, Fitzharris, Young & Lenné, 2013 ).

  • According to STATS19, 2,886 (or 3%) of collisions involving injuries (fatal, serious and slight) in 2016 in GB involved some form of distraction from within the vehicle (RRCGB, DfT, 2017). This is likely to be an underrepresentation due to the difficulties in coding distraction as a contributory factor after the event.

  • The most recent observational count of mobile phone use whilst driving found that 1.6% of drivers in England and Scotland were observed using a hand-held mobile phone whilst driving (DfT, 2015). Drivers were more likely to be holding the phone in their hand (1.1%) rather than holding it to their ear (0.5%). A higher proportion of drivers were observed using a hand-held mobile phone when stationary (2.3%) than in moving traffic (1.6%).

Defining distraction and inattention

  • Driver distraction is a commonly used term, however, it is important to define what is meant by driver distraction for the following reasons:

    • To enable accurate crash causation data to be collected;

    • To develop common measures of driver distraction;

    • To enable comparison of crash and experimental data sources.

  • Due to various definitions of distraction being used historically, many studies are not comparable and confusion regarding whether studies are measuring driver distraction or inattention is common (Lee, Young & Regan, 2008).

  • Various studies have therefore sought to define driver distraction through either:

    1. Analysis of definitions used within published literature (e.g. Lee et al., 2008; Pettit, Burnett & Stevens, 2005), or;

    2. Studies of contributing factors in road crashes (e.g. Hoel, Jaffard and Van Elslande, 2010; Treat, 1980)

    3. Workshops with experts in the subject area (e.g. Basacik & Stevens, 2008; Hedlund, Simpson & Mayhew, 2006).

  • It has been suggested that for future research to be consistent and comparable the following definition of driver distraction by Regan et al. (2011) should be used (Foley, Young, Angell & Domeyer, 2013):

“Driver distraction is the diversion of attention away from activities critical for safe driving toward a competing activity, which may result in insufficient or no attention to activities critical for safe driving.” (p1776)

  • Defining driver inattention has not received the same amount of scrutiny as defining driver distraction. This is possibly because it has often been confused with driver distraction.

  • There has been debate regarding whether driver inattention and driver distraction are separate components, or whether driver distraction is a form of driver inattention (see Regan et al., 2011 for a summary of this debate)

  • The latter perspective appears to be the more prominent in recent models of driver inattention (e.g. Engstöm et al., 2013; Regan et al., 2011) and offer the following definitions:

    • “insufficient, or no attention, to activities critical for safe driving.” (Regan et al., 2011, p1775)

    • inattention occurs when the driver’s allocation of resources to activities does not match the demands of the activities required for the control of safety margins” (Engstöm et al., 2013. p25)

  • Driver inattention as defined by Engstöm et al. (2013) therefore represents attention as all encompassing, representing attentional failures as part of a driver-vehicle-environment system rather than inattention resulting from driver failure alone. Driver distraction is therefore just one form of misdirected attention.

Technology and driving

  • Drivers have access to a wide range of technologies in the vehicle cockpit. They can be either specific to the driving task, such as a navigation system, or more general in purpose, such as a smartphone. Furthermore, these technologies can either be integrated into the vehicle, such as heads-up display (HUD) or a nomadic technology brought into the vehicle by the driver or a passenger, such as a music player.

  • The availability of distracting technologies within the vehicle increases year-on-year. However, there is no clear evidence regarding whether drivers are experiencing more or less distraction today than they have historically. One may speculate that this may be due to improvements in the usability of technologies and increased driver awareness of the appropriate use of technologies, and/or that drivers are adapting their behaviour to the increased attentional demand required when engaging with technology.

  • A wide range of technologies have been subject to investigation, including (but not limited to): mobile phones (including smartphones); satellite navigation systems; entertainment systems; heads-up displays; and smartglasses. These studies usually seek to quantify the probability of and/or the consequences of being distracted by a particular technology in safety critical situations. With the exception of some high-profile studies (e.g. 100-Car study), relatively little research has examined how drivers use technologies in a more naturalistic setting. This limitation in the body of literature goes some way to explaining why there is a disconnect in the frequency of technology related accident rates and predicted risk increase from using said technologies.

  • Experimental evidence suggests that:

    • Texting whilst driving leads to slower reaction times to sudden events, longer glances away from the road and poorer lane control.

    • Both handheld and speech-based texting causes distraction, as does engagement with social media via a smartphone.

    • Hand-held and hands-free mobile phone conversations impact on driving performance to levels somewhat equivalent to that measured when drivers are intoxicated to the level of the drink drive limit in England and Wales.

    • Entertainment and Head-Up Display (HUD) in-vehicle technologies also have the potential to impact on driver performance, although the effects are likely to be device specific.

    • Smartglasses have demonstrated some potential in reducing the level of distraction resulting from engaging in another activity (such as sending and receiving messages), but it does not negate the inevitable distraction effects of engaging in a non-driving related task that requires attentional resources.

    • Drivers appear to engage with satellite navigation devices during periods of low demand, or adapt their driving environment to reduce overall demand (e.g. reducing speed or distance to the vehicle in front) (Metz, Schoch, Just & Kuhn, 2014).

  • Humans have limited attentional capabilities to employ when performing the driving task.

  • It is possible when driving to allocate attentional resources to activities that are not critical for safe driving; these activities may be driving or non-driving related.

  • Technologies that are both driving and non-driving related may have motivational properties that can draw on a driver’s attentional resources (e.g. emotional motivation to answer the phone or read a text, or motivation to re-route a satnav device to avoid congestion).

  • Experimental evidence suggests that where drivers engage in additional tasks, their driving performance is impaired. There is some evidence to suggest that drivers adapt their behaviour to reduce demand when undertaking additional tasks, although this does not appear to negate the impairment completely and drivers are therefore likely to be at greater risk of being involved in a collision when the attentional demands exceed the resources required for the driver-vehicle-environment system.

  • Date Added: 27 Mar 2015, 04:53 PM
  • Last Update: 11 Dec 2017, 04:45 PM