TABLE OF CONTENTS
SUMMARY	III
ZUSAMMENFASSUNG	VII
OVERVIEW	XV
LIST OF FIGURES	XVI
LIST OF TABLES	XVI
LIST OF ABBREVIATION	XVII
1.	INTRODUCTION	1
2.	THEORETICAL BACKGROUND	5
2.1.	The driving task	5
2.1.1.	Hierarchical task model	5
2.1.2.	Motivational models	6
2.2.	Defining driver distraction	8
2.2.1.	Scientific definition of distraction	8
2.2.2.	Driver distraction vs. driver inattention	8
2.3.	Theoretical approaches on secondary/dual-task performance	9
2.3.1.	Multiple resource theory (MRT)	9
2.3.2.	Bottleneck theories	10
2.3.3.	Distraction as breakdown in multilevel control	10
2.3.4.	Minimum required attention theory	12
2.4.	Sources of driver distraction	13
2.5.	Types of NDRTs	14
2.6.	Methods to Assess NDRT Engagement	15
2.6.1.	Surveys/questionnaires	15
2.6.2.	Observation studies	15
2.6.3.	Naturalistic driving studies	15
3.	CURRENT RESEARCH FINDINGS	16
3.1.	Prevalence of NDRTs	16
3.1.1.	Survey studies	16
3.1.2.	Observation studies	17
3.2.	NDRT engagement and crash risk	19
3.2.1.	Phoning	20
3.2.2.	Texting	21
3.2.3.	Using navigation systems	22
3.2.4.	Adjusting vehicle-related settings	22
3.2.5.	Hygiene and clothing	23
3.2.6.	Passenger interaction	23
3.2.7.	Smoking	23
3.2.8.	Distraction from outside the vehicle	24
3.2.9.	Other activities	24
3.3.	Influencing factors on NDRT engagement	24
3.3.1.	Driver characteristics	24
3.3.2.	Psychological factors	25
3.3.3.	Contextual factors	27
3.4.	Driver behaviour while NDRT engagement	28
3.4.1.	Glances durations	28
3.4.2.	Self-regulation	29
4.	OVERALL RESEARCH OBJECTIVES OF THE DISSERTATION	30
4.1.	Development of a valid research methodology for the assessment of NDRTs	30
4.2.	Identification of distracting NDRTs	30
4.3.	Identification of socio-demographic, contextual, and psychological factors influencing the engagement in NDRTs	31
4.4.	Investigation of compensation strategies employed by drivers when engaging in visual–manual NDRTs	31
5.	OVERVIEW OF THE APPLIED METHODOLOGY	31
5.1.	Naturalistic driving study with semi-standardised interviews	32
5.2.	Nationwide interview study	32
5.3.	SHRP2 naturalistic driving study	33
6.	MAIN RESULTS AND DISCUSSION	33
6.1.	Development of a valid research methodology for the assessment of NDRTs	33
6.2.	Identification of distracting NDRTs	35
6.3.	Identification of factors influencing the engagement in NDRTs	37
6.3.1.	Socio-demographic factors	37
6.3.2.	Contextual factors	38
6.3.3.	Psychological factors	39
6.4.	Investigation of compensation strategies employed by drivers when engaging in visual–manual NDRTs	40
6.4.1.	Eye-glance behaviour	40
6.4.2.	Speed adjustments	43
6.5.	Implications	44
6.5.1.	Practical implications	44
6.5.2.	Theoretical implications	49
6.5.3.	Methodological implications	51
6.6.	Limitations	52
6.6.1.	Data collection	52
6.6.3.	Sample	52
6.6.4.	Naïve understanding	54
REFERENCES	55
CURRICULUM VITAE	70
PUBLICATIONS	72
Journal Papers (peer-reviewed)	72
Conference Papers	73
Conference Contributions / Posters / Workshops / Public Research Reports / Whitepapers	73
EIDESSTAATLICHE ERKLÄRUNG	76
PAPER 1	77
PAPER 2	85
PAPER 3	98
PAPER 4	116