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CVEN4405: Human Factors in Civil and Transport Engineering

Early Session Assessment Task 1

Term 3 , 2020

Week 3, Lecture 1a

1

Early Session Assessment

Format: Four short answer questions that requires you to demonstrate an understanding of human factors limitations in a real-world road crash scenario.

Date: Students will be required to write the essay in class time, during Lecture 1a of Week 3. (Wednesday 30th September 2020).

Results and feedback: before Sunday, 11th October 2020 (Week 4).

Prof. Michael Regan, PhD Research Centre for Integrated Transport Innovation

(rCITI) Room 112, Civil Engineering Building (H20)

E: [email protected]

CVEN4405: Human Factors in Civil and Transport Engineering

Vulnerabilities in Human Performance 1:

Fatigue, Drowsiness, Emotion, Arousal, Stress and Strain, Mental Workload

Term 3 , 2020

Week 3, Lecture 1b

4

CVEN 4405 Human Factors in Civil and Transport Engineering

Term 3 2020 Week 3 - Lecture1b

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6

Welcome Back!

7

Course Coodinator and Lecturer

Prof. Michael Regan, PhD Professor of Human Factors

Research Centre for Integrated Transport Innovation (rCITI) School of Civil and Environmental Engineering

University of NSW Sydney

T: +61 (0)2 9385 9504 E: [email protected]

Staff Webpage

8

The CVEN 4405 Teaching Team

Coordinator and Lecturer Prof. Michael Regan Professor of Human Factors Research Centre for Integrated Transport, UNSW Sydney E: [email protected]

Teaching Fellow Dr Prasannah Prabhakharan Research Fellow Research Centre for Integrated Transport, UNSW Sydney E: [email protected]

Demonstrator Mitch Cunningham E: [email protected]

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Review of last lecture

• Reaction Time (RT) • Movement Time • Human Error • Error Management

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Last Weeks Tutorial

• Working Memory • Hick’s Law • Fitt’s Law

» How was it?

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This lecture - Overview

• Fatigue • Drowsiness • Emotion • Arousal • Stress and strain • Mental workload

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Learning Outcomes

CLO1: Explain the fundamental principles of HF that can be used by civil and transport engineers to facilitate user- centred design

CLO2: Apply HF principles, methods and data to the design of road and traffic management systems

CLO3: Plan for the integration of HF into the design lifecycle of the road and traffic management system

Fatigue

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Fatigue

Fatigue is a factor that can impair the performance of any human activity.

We can distinguish between two types of fatigue: 1. Muscular fatigue 2. General fatigue

Muscular fatigue is a painful phenomenon that occurs in over- stressed muscles and is localised.

Source: Oborne (1987), p. 41

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General Fatigue: Definition

General fatigue is, in contrast to Muscular fatigue, • “…a diffused sensation, which is accompanied by feelings of

indolence and disinclination for any kind of activity.”

• Discussion: Who has experienced general fatigue? • What are the symptoms?

Source: Fuller & Santos (2002), p. 87; Grandjean (1981), p. 168

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General Fatigue: Symptoms

The symptoms of general fatigue include: • Subjective feelings of weariness • Decreased motivation • Unwillingness to work • Slowed or impaired perception • Restricted field of attention • Decreased performance, in the form of irregularities in

timing and speed

• Discussion: What are some of the things that cause fatigue, in the rail environment?

Source: Fuller & Santos (2002), p. 87; Grandjean (1981), p. 168

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General Fatigue: Causes

The major causes of generalised fatigue are: • Inadequate sleep • Inadequate rest or recovery • Illness

Source: Fuller & Santos (2002), p. 87

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General Fatigue: Time of Day

People are most alert: • In the mid-morning • In the early evening

People are least alert: • Between midnight a 5am • In the early afternoon (post lunch dip)

Source: PIARC (2016)

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General Fatigue: Circadian Rhythm

Biological factors can have a substantial impact on fatigue, such as the natural circadian rhythm and the amount of sleep they have had.

Fatigue (and sleep-related accidents) most likely to occur in the early hours of the morning between 2am and 6am.

Source: Williamson et al., (2011); Horne & Reyner (1995); Pack et al., (1995); Eskandarian et al., (2007)

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General Fatigue: Inadequate Sleep

People differ in the amount of sleep they need; the amount of sleep needed usually declines with age.

Sleep loss, especially if over several nights, can: • Seriously affect human performance

– E.g. memory, decision making, reaction time, mood

• Be stressful, due to the effort of trying to stay awake • Cause people to fall asleep for a few seconds or less

(“microsleeps”). • Cause people to fall asleep completely

Source: Fuller & Santos (2002), p. 87

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General Fatigue: Inadequate Sleep (2)

Microsleeps may not be noticed but can be dangerous when they occur during the performance of tasks that require continuous attention - like driving or monitoring tasks.

Sleep loss can cause drivers to fall asleep at the wheel. • The onset of sleep can happen very suddenly. • The period just before falling asleep is dangerous,

because drivers have no control over it.

Source: Fuller & Santos (2002), p. 87

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General Fatigue: Inadequate Rest and Recovery Rest and Recovery allows the body to: • replenish muscular energy stores • repair damaged tissues • removes waste from the brain • reduces inflammation

Without sufficient time to repair and replenish, the body cannot perform these tasks, leading to performance decrements.

Source: Kreher & Schwartz (2012), scientificamerica.com

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General Fatigue: Effects of Illness

As we have all experienced, illness can also lead to general fatigue.

• E.g. it is a symptom of COVID-19

However, the focus is of this course is on design (e.g., job design, rostering etc) to minimise potential for fatigue.

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Driver Fatigue: Road Safety

Fatigue effects has been done very well researched, particularly in relation to road safety.

It has been estimated that fatigue is a contributing factor in about 20-30% of road casualties in Australia.

Findings from a recent ‘naturalistic driving study’ in the U.S. showed that driver fatigue/drowsiness increased crash risk by 3.4 times.

Driver fatigue, like driver distraction, is a significant road safety issue.

Source: Australian Transport Council, (2011); Dingus et al., (2016); Cunningham, Regan & Cairney (2017)

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Driver Fatigue: Causes

Driver fatigue may arise from: – driving at particular times of the day or night – driving for prolonged periods – driving in monotonous conditions

» e.g. open highways – driving in complex traffic environments

» e.g. bad weather; at night; unpredictable traffic

Source: Cunningham, Regan & Cairney (2017); PIARC (2016)

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Driver Fatigue: Crash Characteristics

Fatigue-related road crashes typically have several defining characteristics:

– they occur late at night, early morning or mid-afternoon – they result in higher than expected crash severity – they involve a single vehicle leaving the roadway – They occur on a high speed road – the driver did not attempt to avoid the crash – the driver was the sole vehicle occupant

Source: US Expert Panel on Driver Fatigue and Sleepiness (1997); cited in PIARC (2016)

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Driver Fatigue: PIARC Design Recommendations

The PIARC (2016) road design recommendations for fatigue are the same as those for distraction: i.e.

1. Lower energies through conflict points to within human tolerances (by setting speed tolerances)

2. Design to provide opportunities for road users to recover from mistakes and non-compliance.

3. Design to lower the risk of a crash occurring to an “acceptable” level

Source: PIARC (2016)

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Driver Fatigue: Rest Areas

Rest areas have proven safety benefits.

They are located along or beside roadway to: • provide driver with an opportunity to stop driving and sleep/rest/stretch • help driver to counteract the effects of driver fatigue

Careful consideration needs to be given to: • the location of rest areas, particularly along high-speed roads • the best type of facilities to be provided at different locations

Source: PIARC (2016)

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Driver Fatigue: Rest Areas (2)

PIARC (2016) recommendations: • Provide rest areas at regular intervals • Minor rest areas should be located at maximum intervals of

50 km • Major rest areas, with services, should be located at

maximum intervals of 100 km • Provide advance sings offering information relating to

upcoming distance and next rest areas

Source: PIARC (2016)

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Driver Fatigue: Rest Areas (3)

Design Guidance Access into and egress from rest areas are important design

aspects for consideration:

• access and egress must be safe for vehicles entering or leaving the rest area and re-entering the traffic flow

• application and requirements will vary greatly from site to site

Source: Department of Transport and Main Roads (2014); cited in Cunningham, Regan & Cairney (2017)

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Driver Fatigue: Monotony Reduction Treatments Monotony reduction treatments have been developed, but not

all have been evaluated: e.g.

• creating ‘sinuous, rhythmic road alignments’ – i.e. gently winding roads to counter monotony by providing a constantly changing visual field

• avoiding monotonous vegetation and roadside infrastructure along freeways

Source: PIARC (2016), p. 37

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Driver Fatigue: Monotony Reduction Treatments (2) Install simple objects, such as roadside art or signage, to

increase mental stimulation and counteract fatigue along long and monotonous roadways

Must ensure, however, that such installations are located in areas that do not distract drivers from activities critical for safe driving.

Source: Roberts and Turner, (2008) cited in Cunningham, Regan & Cairney (2017)

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Driver Fatigue: Signage and Road Markings

Traffic signs and road markings can be used to:

indicate that a stretch of road has a significant fatigue-related crash risk

identify opportunities to stop (and rest) at designated rest areas or other locations (e.g., service station), with plenty of advanced notice.

Source: Cunningham, Regan & Cairney (2017)

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Driver Fatigue: Rumble Strips

Audio-tactile line markings (“rumble strips”) are small raised bumps on or adjacent to line markings. They:

• alert drivers through both sound and vibration when drifting out of their lane into oncoming traffic or off the edge of the road

• have been proven to be highly effective in reducing crashes

Can be difficult for them to generate a sufficiently loud signal to be effective for heavy vehicles (e.g. trucks)

Source: Wooley & McLean (2006); Cunningham, Regan & Cairney (2017)

Drowsiness

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Drowsiness

The words “drowsiness” and “fatigue” are often used interchangeably, but they are not the same.

While general fatigue can refer to a feeling of tiredness or exhaustion due to inadequate rest, prolonged work or illness, drowsiness refers specifically to the state just before sleep.

You can feel fatigued without feeling sleepy. However, lack of sleep does contribute to general fatigue.

Source: Fuller & Santos (2002), p. 87; https://www.optalert.com/drowsiness-vs-fatigue-how- do-they-differ/

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Drowsiness

• Discussion: What do you think are some of the causes of drowsiness?

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Drowsiness: Causes

The following are the main causes of drowsiness: – not enough sleep – poor quality sleep – sleep disorders e.g. sleep apnoea – radical changes to sleep patterns

» e.g. shift work from day to night – alcohol ingestion – the “post lunch dip” after lunch and/or dinner – drugs with sedative effects

Source: Fuller & Santos (2002), p. 87

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General Tips for Minimising General Fatigue and Drowsiness

In the road safety context: • “get a good night's sleep before heading off on a long trip • don't travel for more than eight to ten hours a day • take regular breaks – at least every two hours • share the driving wherever possible • don't drink alcohol before your trip. Even a small amount can

significantly contribute to driver fatigue • don't travel at times when you'd usually be sleeping • take a 15 minute “powernap” if you feel yourself becoming drowsy”

Source: http://www.tac.vic.gov.au/road-safety/safe-driving/tips-and-tools/fighting-fatigue

Emotion

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Emotion

Emotion can affect the performance of activities undertaken at work or while driving.

It affects performance mainly by: – affecting the functioning of the nervous system – distracting the person from the activity at hand (i.e.

thinking about the thing that is triggering the emotion) Certain intense emotions - such as anger, frustration, anxiety

and fear – can create a state of high state of arousal.

Source: Fuller, 2002, p. 89

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Emotion (2)

Conversely, other emotional states, such as depression and grief, are often associated with low levels of arousal.

There is evidence, from so called “naturalistic driving studies” that driving a car when in an emotional state can increase crash risk by around 10 times.

Whether this is due to over- or –under- arousal of the nervous system, or because of cognitive distraction, is not clear.

Source: Fuller, 2002, p. 89; Dingus et al (2016)

Arousal

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Arousal

• Generally, humans perform best when they are neither under-aroused nor over-aroused (see next slide).

• The next slide shows a function that relates arousal with performance, based on previous research studies.

• It’s called the “Yerkes-Dodson Law.”

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Yerkes-Dodson Law of Arousal

Source: Google

Stress and Strain

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Stress and Strain

Stress can be defined as “some undesirable condition, circumstance, task, or other factor that impinges on the individual”

Strain refers to the effects of the stress

Stress can originate externally or internally, or involve a combination of both:

• External e.g. the work activity, pressures from supervisors • Internal e.g. internal states of the individual, such as fear of

consequences of failure.

Source: Sanders & McCormick (1987), p. 197

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Stress and Strain: Sources of Stress

Source: Sanders & McCormick (1987), p. 198 Source Physiological Psychological

Work • Heavy work• Immobilization

• Information overload • Vigilance • Time pressure • Social pressure

Environment • Atmospheric • Noise/Vibration • Heat/Cold

• Danger • Confinement

Circadian (Diurnal) Rhythm • Sleep loss • Sleep loss

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Stress and Strain (2)

People vary considerably in their response to stressors

Only certain stressors may have an effect any particular individual:

• E.g. for one person, a stressor (e.g. time pressure) might make them feel out of control of their performance

• E.g. for another person, the same stressor might actually improve their performance.

We can’t determine with any reliable tool where a person’s optimum level of stress is, we can try to minimise the level of stress for all.

Source: Fuller & Santos (2002), p. 92

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Stress and Crash Risk (road)

There is evidence that “life stress” increases road crash risk: • self-reported stress  more traffic violations • fatal crashes  5x more likely for stressed vs. non-stressed

drivers • financial issues  higher crash risk • divorce  crash risk increased by 4.4x

Stress can spill over into ones’ driving and other activities we need to perform.

Source: Hartley & El Hassani, (1994); Brenner & Selzer, (1969); Norris et al. (2000); Lagarde et al. (2004)

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Stress & Design

Human Factors professionals have some role in reducing stress by designing the transport environment to, for example:

• reduce operators information overload • reduce time pressure on the operator • reduce operators’ feelings of confinement • modifying the work equipment • modifying the environment • changing work schedules

Source: Derived from Sanders & McCormick (1987), p. 198

Mental Workload

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Mental Workload

• Mental workload can be defined as “the amount of mental effort that is required in order to perform tasks(s)” (Watson, 2002, p. 73)

• Human performance is usually best at optimal levels of mental workload, as it is for arousal.

• If a task or activity is too difficult, performance will likely suffer because humans have a limited quantity of processing resources available to perform a task(s)

Source: Watson, 2002, p. 73

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Mental Workload (2)

If the task is too easy, on the other hand, arousal and alertness may drop off, and performance will also suffer, but this time for a different reason.

(Watson, 2002, p. 73)

Mental workload can be influenced by several factors, most of which can be influenced by traffic engineers:

» The amount of time available to complete a task (workload is usually higher if there is less time available)

Source: Watson, 2002,p. 73

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Mental Workload (3)

• The number of tasks to be performed (workload is higher, the greater the number of tasks, especially if performed simultaneously)

• The required level of accuracy/proficiency

• Individual factors e.g. skill, intelligence, response to stress and personality

• Environmental factors e.g. heat, noise

Source: Watson, 2002, p. 73

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Questions ?

Over to ….

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CVEN 4405 Human Factors in Civil and Transport Engineering

Term 3 2020 Week 3 - Lecture1b

STOP RECORDING

Prof. Michael Regan, PhD Research Centre for Integrated Transport Innovation

(rCITI) Room 112, Civil Engineering Building (H20)

E: [email protected]

CVEN4405: Human Factors in Civil and Transport Engineering

Vulnerabilities in Human Performance 2:

Individual Differences, Alcohol, Other Drugs, Inattention and Distraction

Week 3, Lecture 2

60

CVEN 4405 Human Factors in Civil and Transport Engineering

Term 3 2020 Week 3 - Lecture 2

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Lecture Recordings

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All lectures today are being recorded.

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62

Welcome Back!

63

Course Coodinator and Lecturer

Prof. Michael Regan, PhD Professor of Human Factors

Research Centre for Integrated Transport Innovation (rCITI) School of Civil and Environmental Engineering

University of NSW Sydney

T: +61 (0)2 9385 9504 E: [email protected]

64

Review of last Lecture

• Fatigue • Drowsiness • Emotion • Arousal • Stress and strain • Mental workload

65

This lecture - Overview

• Individual differences • Alcohol • Other drugs • Inattention and distraction

66

Learning Outcomes

CLO1: Explain the fundamental principles of HF that can be used by civil and transport engineers to facilitate user- centred design

CLO2: Apply HF principles, methods and data to the design of road and traffic management systems

CLO3: Plan for the integration of HF into the design lifecycle of the road and traffic management system

Individual Differences

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Individual Differences

Individuals differ on both physical and psychological characteristics

• We have talked about physical differences in size and shape, and the science of Anthropometry, in previous lectures.

Individuals differ on various stable psychological characteristics e.g. intelligence and personality.

Individuals may also become different, over time, as they age and become more experienced.

Source: Fuller & Santos (2002), p. 91

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Individual Differences (2)

It’s important to understand the range of individual differences NOT so we can try to identify or blame “at risk” individuals.

Rather, its important to understand the range of individuals differences so we can predict worst-case scenarios and aim for “universal design”

• i.e., design that is suitable for a range of ages, minimises stress, anticipates and accommodates error potential due to risky behaviour, allows for varying levels of experience.

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Individual Difference (3)

We will cover a few individual differences which have implications for safety in the rail environment:

• Personality • Response to Stress • Experience • Age

Source: Fuller & Santos (2002), p. 91

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Individual Difference: Personality

Personality can categorised according to the five-factor model of personality - the “big five” personality dimensions.

These factors exist across cultures

Have a genetic basis and that they are likely inherited.

Personality traits tend to remain relatively stable over the lifespan but do change.

• Over a period of years/decades not days/months.

Source: Rothmann & Coetzer (2003); Google Images.

Acronym ‘OCEAN’

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Individual Difference: Personality (2)

1. Openness to Experience (or Imagination) includes traits such as:

• active imagination • aesthetic sensitivity • attentiveness to inner feelings • a preference for variety • intellectual curiosity • independence of judgement.

Source: Rothmann & Coetzer (2003)

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Individual Difference: Personality (3)

2. Conscientiousness. Includes traits such as – Good self-control – Good at planning, organising and carrying out tasks – Purposeful – Strong-willed and Determined – Achievement orientated – Dependability – Orderliness

Source: Rothmann & Coetzer (2003)

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Individual Difference: Personality (4)

3. Extraversion. Includes traits such as – Sociability – Assertiveness – Activity – Talkativeness – Energetic – Optimistic

Introverts on the other hand are reserved, independent, even-paced.

4. Agreeableness. Includes traits such as – fundamentally altruistic – sympathetic to others and eager to help them – in return believes that others will be equally helpful

Source: Rothmann & Coetzer (2003)

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Individual Difference: Personality (5)

5. Neuroticism (or Emotional Stability) • The general tendency to experience negative affects such as

– Fear – Sadness – Embarrassment – Anger – Guilt – Disgust

Source: Rothmann & Coetzer (2003)

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Individual Difference: Response to Stress

There is wide variability in how individuals respond to stressors

• E.g. Time pressure might cause one person to feel a complete lack of control over their driving options whereas another individual might be motivated to increase their level of performance

Emotional, Psychological and Physical effects of stressors tend to be specific and to affect only certain individuals

Source: Fuller & Santos (2002), p. 92

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Individual Difference: Experience

Inexperienced drivers are typically more prone to error and to having crashes.

Given a particular road and traffic scenario they may: • Not know the correct manoeuvre so they try a different manoeuvre which

turns out to be unsafe • Not know how to carry out a particular manoeuvre correctly; • Not have enough experience of dealing safely with the effects of human

factors on their performance.

Source: Fuller & Santos (2002), p. 92

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Individual Difference: Age

With age, physiological changes occur which have implications for how we perform as road users.

We talked about these for the visual and auditory systems in a previous lecture. e.g.

• Lighting requirements for a given task may increase • The speed with which the eye adapts to light or dark, decrease • Hearing sensitivity decreases, especially at the upper end of the

frequency range

In general, there is a loss of strength, flexibility and tolerance of fatiguing conditions, especially when working at night.

Source: Fuller & Santos (2002), p. 92

Alcohol

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Alcohol

• Alcohol and other drugs can influence various stages of human information processing and, ultimately, degrade performance.

• The liver can only metabolise (break down) alcohol at a fixed rate, regardless of how much has been consumed by an individual.

• For most people, our liver can metabolise it at the rate of around X standard drinks per hour. What’s the number?

• Consequently, even if we consume alcohol long before we perform an activity (e.g. drive a car), alcohol can still affect performance.

Source: Fuller, 2002, p. 87

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Alcohol (2)

• If we drink 2 standard drinks in 1 hr on an empty stomach, we lose inhibitions and some loss of coordination for an hour.

• If we drink 4 standard drinks in 1 hr, it will lead to faulty decision making and further loss of coordination, along with drowsiness. Here, performance and safety will be affected for 3 hrs

• Having 6 standard drinks in 1 hr will slow reaction time significantly, and affect driving for 5 hrs.

Source: Fuller, 2002, p. 87

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Alcohol (3)

• For drivers, alcohol also affects driving performance by bringing the point of visual fixation of the driver closer to the front of the vehicle.

• This prevents the driver from effectively detecting hazards ahead, reacting in anticipation to hazards and planning manoeuvres.

• In road safety alcohol is, not surprisingly, a major factor contributing to road crashes. What do you think is the size of the problem? Ho wmany peopl

• We will talk later in the course about what role traffic engineers might play in designing the road environment in relation to alcohol intoxication.

Other Drugs

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Other Drugs

• Apart from alcohol and minor tranquilisers, not a great deal is known about which drugs, at what doses, impair road user performance and road safety.

• There is evidence that benxodiazepine users (e.g. Valium) are over-represented in crashes, and that cannabis impairs driving performance.

• However, the relationship between cannabis ingestion and crash causation remains unclear; although Police test for the presence of cannabis in some jurisdictions

Source: Fuller, 2002, p. 87

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Other Drugs (2)

• In Victoria, around18% of drivers and motorcyclists killed on the state's roads test positive to THC (in cannabis)

• Cannabis tends to make people drive too slowly, find it difficult to stay awake, and stay within their designated lanes.

• Amphetamines and ecstasy tend to lead to speeding or erratic driving as well as reduced vision and increased risk taking behind the wheel.

• Source: Fuller, 2002, p. 87; https://adf.org.au/insights/drugs-and-driving/

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Other Drugs (3)

• Combining alcohol and other drugs can further impair driving performance.

• Determining the relationship between drug dose levels and increased crash risk is complex and the relationship is still largely unclear.

• It is clear, however, that drugs can impair human performance.

• Source: Fuller, 2002, p. 87; https://adf.org.au/insights/drugs-and-driving/

Inattention & Distraction

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Inattention

• In Wickens’ model, attention is required for several stages of information processing - perception, working memory, decision making and response execution.

• It follows that, if we don’t pay attention to what we are doing (e.g. driving), some stages of information processing will not proceed properly, or at all, resulting in degraded performance and error.

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Inattention: Definition and Mechanisms

Inattention is a contributing factor to about 65% of fatal and serious injury road crashes and has been defined as:

• “insufficient or no attention to activities critical for safe driving” • Similar figure are seen in a rail context, with ‘attentional factors’

contributing to around 70% of all rail incidents

While this lecture, will focus on inattention and driving, in the road context, the theory and principles can be applied to rail.

There are several different mechanisms of inattention. They have been defined by Regan, Hallett & Gordon (2011)

• Distraction is just one mechanism of inattention.

Source: Regan, Hallett & Gordon (2011), p. 1775; Edkins & Pollock (1997).

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Driver Inattention

Driver Restricted Attention

Driver Misprioritised Attention

Driver Neglected Attention

Driver Cursory Attention

Driver Diverted Attention (Distraction)

Driving-Related

Taxonomy of Inattention

Source: Adapted from Regan, Hallett & Gordon (2011)

• Task-unrelated thoughts • Internal/Intentional • Internal/Unintentional • External/Intentional • External/Unintentional

• Daydreams

• Task-related thoughts

Non-Driving-Related

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Driver Inattention: Examples (1)

Driver restricted attention • e.g. Driver dozes off momentarily, with eyes closed, and almost hits a

pedestrian crossing the street ahead

Driver misprioritised attention • e.g. Driver looks over their shoulder for too long while merging and fails

to see a lead vehicle rapidly braking

Source: Regan, Hallett & Gordon (2011)

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Driver Inattention: Examples (2)

Driver neglected attention • e.g. Driver neglects to scan to the left for approaching trains at a railway

level crossing, because s/he does not expect trains to be there (because they are rarely or never seen)

Driver cursory attention • e.g. Driver in a hurry does not complete a full head check when merging

onto a highway and collides with a merging car

Source: Regan, Hallett & Gordon (2011)

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Driver Inattention: Examples of Distraction

Driver diverted attention (distraction) – non-driving related: • e.g. Driver looks at cell phone while dialling a friend • e.g. Driver thinks about what needs to be done when s/he gets to work • e.g. Driver daydreams about a romantic holiday in Paris

Driver diverted attention (distraction) – driving-related: • e.g. Driver looks at unexpected a flashing low fuel warning light • e.g. Driver thinks constantly about where to find nearest service station,

because the fuel tank is almost empty

Source: Regan, Hallett & Gordon (2011)

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Driver Distraction: Definition & Mechanisms

• Driver diverted attention (i.e. distraction) has been defined as:

– “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”

• When a driver is distracted, they take their: • Eyes off the road (“visual distraction”) • Mind (attention) off the road (“cognitive distraction”) • Ears off the road (“auditory distraction”) • Hand(s) off the steering wheel (“physical interference”)

Source: Regan, Hallett & Gordon (2011); Regan & Hallett (2011)

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Driver Distraction: Definition & Mechanisms

As a result, driving performance is usually degraded unless the driver is capable of timesharing between the driving task and the distracting task that is competing for their attention.

Source: Regan, Hallett & Gordon (2011)

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Driver Distraction: General Sources

Objects (e.g., mobile phone; advertising billboard) Events (e.g. lightning; explosion) Passengers Other road users and vehicles Animals Internal stimuli (that stimulate internal thought)

Around 30% of distraction-related crashes derive from driver engagement with sources of distraction that are from outside the vehicle

Source: Regan, Hallett & Gordon (2011); Gordon (2009)

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Driver Distraction: External Sources (2)

External sources in the road environment, that have contributed to crashes include:

• Animals and Insects • Architecture and Landmarks • Road signs and Advertising • Construction zones/equipment • Crash scenes • Incidents (e.g. road rage) • Other Road users and vehicles • Scenery • Weather (e.g. lightning).

Source: Gordon (2009)

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Driver Distraction: Impact on Performance

Driving performance is usually degraded by distraction unless the driver is capable of timesharing between the driving task and the distracting task that is competing for their attention.

If a driver is not capable of timesharing between the driving task and the distracting task that is competing for their attention, performance will be degraded and crash risk increases.

It is estimated that distraction contributes to around 16% of serious injury and fatal crashes in Australia

Source: Beanland et al (2013)

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Mind off the Road: Impact on Driving

Selecting information: • gaze concentration – increased eye focus on road straight ahead • Less attention to peripheral field- eg neglect checking rear-view mirrors,

speedometer, peripheral hazards

Processing information: • “inattention blindness” – pedestrian walks from behind parked car; you

look at him, but don’t respond, or respond late • memory loss - fail to remember what has been seen during drive

Source: Bayley et al. (2009); Horberry & Edquist (2009); Bruyas (2013)

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Mind off the Road: Impact on Driving (2)

Driving performance: • response time increases – resulting in more hard braking • look less at traffic lights – and miss red lights • more navigation errors • improved lane keeping performance – gaze concentration • no appreciable impact on following distances • accept shorter gaps when turning right across traffic • small decreases in speed; greater decreases if holding the phone

Source: Bayley et al. (2009); Horberry & Edquist (2009); Bruyas (2013)

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Mind off the Road: Impact on Driving (2)

Driving performance (cont): • fewer lane changes – compensation • conflicts with vulnerable road users • more violations (speeding; red light running; crossing solid lines) • reduced ability to cope with wind gusts • errors – stopping at green lights; taking off before light green • Reduced scanning of intersection areas to the right • reduction in situation awareness – less able to identify, locate and

respond to hazardous vehicles and to avoid accidents.

Source: Bayley et al. (2009); Horberry & Edquist (2009); Bruyas (2013)

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Eyes off the Road: Impact on Driving

Selecting information: • miss relevant information from roadway • gaze concentration - when eyes return to the roadway

Processing information: • Longer reaction times to roadway warnings and braking lead

vehicles • change blindness – disrupts detection of changes in the

road scene

Source: Bayley et al. (2009); Horberry & Edquist (2009); Bruyas (2013); Victor et al (2009)

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Eyes off the Road: Impact on Driving (2)

Driving performance: • lane keeping – worse; drive where you look • speed – reduce speed more with visual-manual distraction • following distance – increases more with visual-manual

distraction • more collisions

Source: Bayley et al. (2009); Horberry & Edquist (2009); Bruyas (2013); Victor et al (2009)

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Hands off Wheel: Impact on Driving

Hypotheses: • one hand on wheel (automatic vehicle) = reduced steering

control during turns and emergency situations

• one hand on wheel (manual vehicle) = as above + reduced gear-changing control

• Steering with knees = as above + reduced speed control + longer RT to brake

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Driver Distraction: Prevention & Mitigation

In road safety, many strategies are available for preventing and mitigating the effects of distraction. These include:

» Research » Road and Traffic Engineering and Design » Data Collection and Evaluation » Education and Training » Employers

Source: Regan & Oviedo-Trespalacios (2020 – in press)

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Driver Distraction: Prevention & Mitigation (2)

– Legislation and Enforcement – Licencing – Stakeholder Coordination – Technology Design – Vehicle Design

Source: Regan & Oviedo-Trespalacios (2020 – in press)

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Questions ?

Over to ….

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CVEN 4405 Human Factors in Civil and Transport Engineering

Term 3 2020 Week 3 - Lecture1b

STOP RECORDING

Prof. Michael Regan, PhD Research Centre for Integrated Transport Innovation

(rCITI) Room 112, Civil Engineering Building (H20)

E: [email protected]