The psychology of driving automation: A discussion with Professor Don Norman

Introducing automation into automobiles had inevitable consequences for the driver and driving. Systems that automate longitudinal and lateral vehicle control may reduce the workload of the driver. This raises questions of what the driver is able to do with this 'spare' attentional capacity. Research in our laboratory suggests that there is unlikely to be any spare capacity because the attentional resources are not 'fixed'. Rather, the resources are inextricably linked to task demand. This paper presents some of the arguments for considering the psychological aspects of the driver when designing automation into automobiles. The arguments are presented in a conversation format, based on discussions with Professor Don Norman. Extracts from relevant papers to support the arguments are presented

Safe driving in a green world : a review of driver performance benchmarks and technologies to support ‘smart’ driving

Road transport is a significant source of both safety and environmental concerns. With climate change and fuel prices increasingly prominent on social and political agendas, many drivers are turning their thoughts to fuel efficient or ‘green’ (i.e., environmentally friendly) driving practices. Many vehicle manufacturers are satisfying this demand by offering green driving feedback or advice tools. However, there is a legitimate concern regarding the effects of such devices on road safety – both from the point of view of change in driving styles, as well as potential distraction caused by the in-vehicle feedback. In this paper, we appraise the benchmarks for safe and green driving, concluding that whilst they largely overlap, there are some specific circumstances in which the goals are in conflict. We go on to review current and emerging in-vehicle information systems which purport to affect safe and/or green driving, and discuss some fundamental ergonomics principles for the design of such devices. The results of the review are being used in the Foot-LITE project, aimed at developing a system to encourage ‘smart’ – that is safe and green – driving

Measuring working memory load effects on electrophysiological markers of attention orienting during a simulated drive

Intersection accidents result in a significant proportion of road fatalities, and attention allocation likely plays a role. Attention allocation may depend on (limited) working memory (WM) capacity. Driving is often combined with tasks increasing WM load, consequently impairing attention orienting. This study (n = 22) investigated WM load effects on event-related potentials (ERPs) related to attention orienting. A simulated driving environment allowed continuous lane-keeping measurement. Participants were asked to orient attention covertly towards the side indicated by an arrow, and to respond only to moving cars appearing on the attended side by pressing a button. WM load was manipulated using a concurrent memory task. ERPs showed typical attentional modulation (cue: contralateral negativity, LDAP; car: N1, P1, SN and P3) under low and high load conditions. With increased WM load, lane-keeping performance improved, while dual task performance degraded (memory task: increased error rate; orienting task: increased false alarms, smaller P3). Practitioner Summary: Intersection driver-support systems aim to improve traffic safety and flow. However, in-vehicle systems induce WM load, increasing the tendency to yield. Traffic flow reduces if drivers stop at inappropriate times, reducing the effectiveness of systems. Consequently, driver-support systems could include WM load measurement during driving in the development phase

Miles away. Determining the extent of secondary task interference on simulated driving

There is a seemingly perennial debate in the literature about the relative merits of using a secondary task as a measure of spare attentional capacity. One of the main drawbacks is that it could adversely affect the primary task, or other measures of mental workload. The present experiment therefore addressed an important methodological issue for the dual-task experimental approach – that of secondary task interference. The current experiment recorded data in both single- and dual-task scenarios to ascertain the level of secondary task interference in the Southampton Driving Simulator. The results indicated that a spatial secondary task did not have a detrimental effect on driving performance, although it consistently inflated subjective mental workload ratings. However, the latter effect was so consistent across all conditions that it was not considered to pose a problem. General issues of experimental design, as well as wider implications of the findings for multiple resources theory, are discusse

Driver behaviour with adaptive cruise control

This paper reports on the evaluation of adaptive cruise control (ACC) from a psychological perspective. It was anticipated that ACC would have an effect upon the psychology of driving, i.e. make the driver feel like they have less control, reduce the level of trust in the vehicle, make drivers less situationally aware, but workload might be reduced and driving might be less stressful. Drivers were asked to drive in a driving simulator under manual and ACC conditions. Analysis of variance techniques were used to determine the effects of workload (i.e. amount of traffic) and feedback (i.e. degree of information from the ACC system) on the psychological variables measured (i.e. locus of control, trust, workload, stress, mental models and situation awareness). The results showed that: locus of control and trust were unaffected by ACC, whereas situation awareness, workload and stress were reduced by ACC. Ways of improving situation awareness could include cues to help the driver predict vehicle trajectory and identify conflicts

A proposed psychological model of driving automation

This paper considers psychological variables pertinent to driver automation. It is anticipated that driving with automated systems is likely to have a major impact on the drivers and a multiplicity of factors needs to be taken into account. A systems analysis of the driver, vehicle and automation served as the basis for eliciting psychological factors. The main variables to be considered were: feed-back, locus of control, mental workload, driver stress, situational awareness and mental representations. It is expected that anticipating the effects on the driver brought about by vehicle automation could lead to improved design strategies. Based on research evidence in the literature, the psychological factors were assembled into a model for further investigation

Smart driving aids and their effects on driving performance and driver distraction

In-vehicle information systems have been shown to increase driver workload and cause distraction; both of which are causal factors for accidents. This simulator study evaluates the impact that two designs for a smart driving aid, and scenario complexity have on workload, distraction and driving performance. Results showed that real-time delivery of smart driving information did not increase driver workload or adversely effect driver distraction, while having the effect of decreasing mean driving speed in both the simple and complex driving scenarios. Subjective workload was shown to increase with task difficulty, as well as revealing important differences between the two interface designs

Response to automatic speed control in urban areas: A simulator study.

Speed affects both the likelihood and severity of an accident. Attempts to reduce speed have centred around road design and traffic calming, enforcement and feedback techniques and public awareness campaigns. However, although these techniques have met with some success, they can be both costly and context specific. No single measure has proved to be a generic countermeasure effective in reducing speed, leading to the suggestion that speed needs to be controlled at the source, i.e. within the vehicle. An experiment carried out on the University of Leeds Advanced Driving Simulator evaluated the effects of speed limiters on driver behavionr. Safety was measured using following behaviour, gap acceptance and traffic violations, whilst subjective mental workload was recorded using the NASA RTLX. It was found that although safety benefits were observed in terms of lower speeds, longer headways and fewer traffic light violations, drivers compensated for loss of time by exhibiting riskier gap acceptance behaviour and delayed braking behaviour. When speed limited, drivers' self-reports indicated that their driving performance improved and less physical effort was required, but that they also experienced increases in feelings of frustration and time pressure. It is discussed that there is a need for a total integrated assessment of the long term effects of speed limiters on safety, costs, energy, pollution, noise, in addition to investigation of issues of acceptability by users and car manufacturers

Driver hand positions on the steering wheel while merging into motorway traffic

It has been suggested that a driver's hand position on the steering wheel can reflect the perceived risk of the road context (Walton, D., & Thomas, J. A. (2005). Naturalistic observations of driver hand positions. Transportation Research Part F, 8. 229-238, Thomas, J. A., & Walton, D. (2007). Measuring perceived risk: Self-reported and actual hand positions of SUV and car drivers. Transportation Research Part F, 10, 201-207). These original studies were based on field observations where only a part of the steering wheel could be viewed. In the present study hand positions were observed in a driving simulator during the performance of a demanding task: merging into motorway traffic. In the current study the whole steering wheel could be observed and hand positions were classified in three categories: high control, medium control, and low control. Differences in hand position between different traffic conditions were limited, and hand position did not correlate with self-reported risk or self-reported mental effort, but changes in hand positions do seem to be associated with changes in workload demand. It is therefore concluded that hand position can give some information about mental workload. (C) 2010 Elsevier Ltd. All rights reserved