Summary and implications for behavioural adaptation

This chapter described an online driver survey which examined a range of IVNS user responses and compared IVNS users with non-users in terms of the frequency with which they reported engagement in aberrant driving behaviours from the DBQ, positive driving behaviours as well as other items related to navigational efficiency.

The online survey methodology achieved reasonable external validity in terms of age, gender, socio-economic status and driving experience, although due to problems associated with self-selection, the sample probably contained more IVNS and driving enthusiasts than are typically found in the general driving population. The responses of IVNS users and non-users were compared for several items. The results suggested that the socio-economic divide between IVNS users and non-users has become increasingly smaller, and that most IVNS users are aged between 21 and 40 years.

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insufficient detail of non-user information collected, the potential influence for response biases and characteristics of the internet sample, there were some important differences found between IVNS users and non-users that have implications in terms of behavioural adaptation to IVNS.

The first aim of the thesis was to identify different types of behavioural adaptation to IVNS affecting contemporary drivers, including those which have a positive, negative and neutral impact on driving safety and navigational efficiency. Importantly the majority of respondents reported that they were satisfied with their IVNS indicating that acceptance (a pre-requisite of behavioural adaptation – see chapter 2) among the present sample was probably quite high.

Concerning the DBQ items specifically related to driving safety there were few significant differences in the relative frequency with which IVNS users and non-users reported engagement in a range of driving errors. The most notable exception was that IVNS users reported driving while distracted significantly more frequently than non-users, but this was a violation item (i.e. a deliberate action rather than an accidental one). For all other safety-related DBQ items, where differences were found they suggested that IVNS users behaved more safely than non-users.

In terms of navigational efficiency, responses largely indicated positive strategic level behavioural adaptation to IVNS, as IVNS users reported making fewer tactical level navigational errors (i.e.

misreading signs on roundabouts and junctions) than non-users. Also more than a quarter of IVNS-using respondents reported that since acquiring their system they have made more unfamiliar journeys than they used to. However, the majority of respondents reported no change in their exploration of unfamiliar areas since acquiring an IVNS, although over half did report feeling more confident when driving through unfamiliar areas, which suggests that some users are receiving some of the intended benefits of IVNS in terms of navigational efficiency.

Part of the second aim of the thesis was to identify individual difference variates in drivers’ experiences of behavioural adaptation to IVNS. The present study highlighted several interesting significant associations between responses to section 2 items and a range of driver and IVNS user characteristics, suggesting that in addition to IVNS usage, a whole range of other factors are also associated with the frequency with which IVNS users engage in the various driving behaviours reported. However, this section did not address the second thesis aim because that was concerned with identifying individual differences variates in drivers’ experiences of safety-negative behavioural adaptation to IVNS, and as

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a map or navigation system display” the driver survey indicated only positive IVNS user behavioural adaptation in terms of driving safety. Nevertheless the significant correlations that were identified highlight the added importance of individual difference variables in understanding driver behavioural adaptation to IVNS.

A major limitation of the present study was that due to constraints on the length of the online survey, the small amount of IVNS usage information collected lacked sufficient detail. Further research is urgently required to understand precisely how drivers use their IVNS and some of the contexts in which usage occurs. Usage will also need to be defined more rigorously so it is clear whether participants are referring to following system instructions, physically interacting with their IVNS while driving or some other user behaviour. Although driver trust in IVNS was briefly examined, issues related to over-reliance and components of trust in IVNS were also neglected. These issues are important aspects of behavioural adaptation to IVNS that have received limited attention in the literature so far.

In conclusion, although the present study highlighted some important differences between drivers who use and do not use IVNS and associations between driver/IVNS user characteristics and experiences of behavioural adaptation to IVNS, a number of issues (particularly aspects of safety-negative behavioural adaptation to IVNS) still require much more detailed investigation before the first two aims of the thesis can be considered fully addressed. To accomplish this, a second online survey was designed to target a much higher number of IVNS users only, and to investigate issues that went unexamined, or that were examined in insufficient detail in the present study (see chapter 4).

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4.1 Introduction

This chapter describes a second survey, this time aimed solely at IVNS users. Due to the high volume and wide range of IVNS users recruited for the previous survey, as well as the other advantages cited in the previous chapter, this survey was also conducted online. As shown in chapter 3, to reduce dropout and increase questionnaire attractiveness to potential respondents, the length of the survey was constrained. Although there were some methodological limitations, the driver survey made a contribution to the first aim of the thesis by highlighting significant differences in the self-reported driving behaviour of IVNS users and non-users. However, there remain significant gaps specifically concerning IVNS user-behaviour and negative behavioural adaptation to IVNS (in terms of safety).

The present study aimed to further address the first aim of the thesis by identifying behavioural adaptations which can degrade driving safety, but have received little previous research attention and were insufficiently addressed in the previous study. By recruiting a large and culturally diverse sample of IVNS users, it also aimed to partially address the second aim of the thesis by identifying stable user trends within the sample population as well as any salient individual difference variates in drivers’

experiences of behavioural adaptation to IVNS. No established scales were employed here because this study was intended to examine issues that have received little or no previous research attention, but all items were piloted before being included in the final survey (see appendix E).

As the previous study collected only limited IVNS usage information, the present study was also designed to investigate IVNS usage in much greater detail than before, as it is such an important aspect of behavioural adaptation. In particular the IVNS user survey aimed to find out how, and to what extent, drivers use their IVNS in familiar and unfamiliar areas. These items were not meant to examine system interaction¹, but more the level of navigational assistance that drivers wish to receive when driving in familiar and unfamiliar areas. Following Svahn (2004) respondents were asked to rate the relative frequency² with which they engage in passive and active system usage when driving in familiar and unfamiliar areas³. Svahn (2004, p.11) defined active system usage as “ a destination is configured. The

1 System interaction is addressed elsewhere in the questionnaire

2 These items used the same ordinal scale as section 2 items in the previous study

3 Svahn (2004) also distinguished basic system usage where the system is merely turned on, but this category was not included in the present study

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and passive system usage as “the system is used, without an active route, and consequently no destination....this kind of system usage will mainly provide situation awareness and orientation” .

4.2 Main objectives

The main objectives of this study were to:

1. Address the first two aims of the thesis by exploring behavioural adaptation issues that were insufficiently addressed in the previous driver survey, particularly those which have the potential to degrade driving safety⁵ such as over-reliance and manual system interaction while driving.

2. Further address the second aim of the thesis by identifying any individual difference variates in the extent to which drivers show behavioural adaptation to IVNS.

4.3 Method