Seguridad Social

This thesis is comprised of 11 chapters (shown in Figure 1-1) and three appendices.

Figure 1-1: Thesis structure

Chapter 2 is a synthesis of the literature on driving risk, risky driving behaviour and research methods for capturing driver behaviour. Section 2.2 examines the literature on the frequency and impact of the most common forms of risky driving behaviour with a particular emphasis on speeding, acceleration and braking as these are the focus of this research. Section 2.3 examines the literature on exposure and other

sources of risk that are exogenous to the driver. Section 2.4 reviews the literature on collection of driver behaviour data including surveys, crash data, simulators and naturalistic driving.

Chapter 3 reviews the literature on the factors that influence driver behaviour, methods of categorising drivers and concludes with identifying the research gaps identified from the literature review. Specifically, Section 3.1 reviews the literature on the relationship between driver behaviour and the road environment,

demographics, personality, enforcement and risk perception. Section 3.2 summarises the existing literature on behavioural responses to the provision of information. Section 3.3 identifies prior research on categorising drivers on a number of measures including demographics, risk perceptions and observed behaviour.

Chapter 4 describes the study design and methodology that are used in this thesis. The hypotheses that are tested are outlined in detail in Section 4.1. The data that are used to examine the hypotheses are described in Section 4.2. Lastly, an overview of the analysis and methodological approaches are introduced in Section 4.3.

Chapter 5 is a detailed technical discussion of how the datasets employed in this research were stored, cleaned, processed and merged. Section 5.1 describes how the data were stored and queried using relational databases. Section 5.2 deals with the algorithms that were developed to identify the spatial characteristics which were relevant to each GPS observation. Section 5.3 explains how the raw GPS data were used to determine where and when drivers engaged in speeding, aggressive

acceleration and aggressive braking behaviour as well as the techniques used to

correct and smooth the data. Section 5.4 discusses two methods for aggregating the 80 million GPS observations to a manageable level. Lastly – and distinctly – the

demographic, psychological and exit surveys are explained in Section 5.5.

Chapter 6 is the first of three results chapters. It presents a number of analyses selected to illustrate the inherent issues in trying to study driver behaviour with data collected during day-to-day driving outside a controlled environment and the poor model performance that occurs as a consequence. Section 6.1 is an exploratory

analysis of (primarily) speeding behaviour at an aggregate level. Section 6.2 contains ANOVA, logistic regression and clustering analyses of driver behaviour using overall speeding for each driver as the dependent variable. Section 6.3 describes the best performing logistic regression models performed using data aggregated to the road segment. Section 6.4 provides some concluding commentary on the results and problems of the models in this section.

Chapter 7 introduces Temporal and Spatial Identifiers (TSI) which is a methodology developed to control for the influence of spatiotemporal factors on driver behaviour and thereby resolve some of the problems identified in Chapter 6. Section 7.1 and Section 7.2 identify the spatial and temporal factors respectively that are accounted for. Sections 7.3 to 7.6 comprise of a technical discussion on how the TSIs are

identified, created and subsequently used as the basis for aggregating observations. Section 7.7 and Section 7.8 assess the characteristics and effectiveness of this

approach. Lastly, Section 7.9 and Section 7.10 describe how this methodology can be applied in practice.

Chapter 8 describes the development of driver behaviour profiles (DBP) which has been developed as a tool for measuring driver behaviour on a consistent scale while accounting for differences in magnitudes and frequencies. Sections 8.1 to 8.3 outline the framework behind this methodology and how the DBPs can be interpreted.

Section 8.4 describes – in detail – the algorithm used to calculate the driver behaviour profiles as well as the changeable options and the final output. Section 8.5 explains the rationale behind the (customisable) weights that have been applied in the

algorithm for the speeding, acceleration, braking and composite scores. This chapter concludes with Section 8.6 which explains how driver behaviour profiles can be used to compare behaviour between and within drivers.

Chapter 9 is the second of three results chapters and contains the results for the first set of hypotheses which relates to the extent of risky driving behaviour in day-to-day driving. Section 9.1 explains the methodology that is used and provides some

explanatory analyses. Hypothesis 1.1 which deals with perceptions of risk is discussed in Section 9.2. The results for Hypothesis 1.2 which relates to drivers‘ concern of

injury while driving are presented in Section 9.3. Hypothesis 1.3, relating to driving confidence, is examined in Section 9.4. Hypothesis 1.4 which examines the

relationship between personality and risky driving behaviour is presented in Section 9.5. A summary and discussion of the results of the first set of hypotheses can be found in Section 9.7.

Chapter 10 is the last of three results chapters and contains the results for the second set of hypotheses. These hypotheses relate to how the magnitude of changes in risky driving behaviour that occur after the introduction of financial and speeding

awareness interventions relate to risk perceptions (Section 10.2), concern of injury (Section 10.3), driving confidence (Section 10.4) and personality (Section 10.5). The conclusions that can be drawn from these results are discussed in Section 10.7.

Chapter 11 contains the implications of these results for policy and research. Section 11.2 contains the implications for policy, which are comprised of five aspects. These include changing the road environment, changing risk perceptions, improving

speeding awareness, introducing financial incentives to reduce speeding and effective targeting of hard and soft measures for different groups of drivers. Section 11.3 contains a discussion on the research implications which include accounting for the road environment, using driver behaviour profiles for research and implications of these findings for before-and-after studies. The limitations of this research are discussed in Section 11.4. A path for future research is outlined in Section 11.5. The chapter (and thesis) concludes with some brief final remarks in Section 11.6.

Appendix A (Chapter 13) breaks each of the sub-hypotheses into its constituent parts and summarises if they could be accepted or not. Appendix B (Chapter 14) provides a discussion on a number of additional models that were run in the process of testing the first set of hypotheses (Chapter 9) but proved to not be beneficial. Nonetheless, they are provided as background as they contain some observations which have been excluded from the remaining models. Appendix C (Chapter 15) presents a number of models that have been reduced using a step-wise procedure. These are included as background material since the results chapters (Chapter 9 and Chapter 10) include only the full models.

2 LITERATURE REVIEW: ‘RISKY’ DRIVING BEHAVIOUR

This chapter reviews the literature on the extent of the most common forms of risky driving behaviour: speeding, fatigued driving and drink driving which are each contributing factors in between 20 and 34 percent of fatal crashes4 _(Australian

Transport Council, 2010), and other forms of risky driving behaviour such as

distractions, aggressive acceleration and aggressive braking. The outcome of these behaviours in terms of road injuries and fatalities are discussed here5_{. This chapter}

also includes a review of the literature in measuring behaviour and exposure. Although fatigue and drink driving are significant contributors to fatalities they are not examined explicitly in this thesis. However, some of the symptoms of fatigued and drink driving are measured by virtue of the effects on drivers‘ speed, acceleration and braking behaviour. These effects are discussed in this literature review.