Kristie Young

1
Kristie Young

• Driver Distraction Effects on Driver Performance
  and Safety

2
Overview

• Sources - What distracts drivers?
• Exposure - Who is distracted and how often?
• Impact - How does distraction from various
  sources affect driving performance?
• Moderating factors Who is most vulnerable?
• Crashes How big is the problem?

3
Sources of Distraction

• The book identifies seven main categories into
  which known sources of distraction can be
  classified
• Things Brought into Vehicle (food, pet, mobile
  phone, PDA)
• Vehicle Systems (entertainment system, vehicle
  controls)
• Vehicle Occupants (adult, child)
• Moving Object or Animal in Vehicle
• Internalized Activity (coughing, daydreaming)
• External Objects, Events or Activities
  (billboards, pedestrians, scenery)
• Other Sources of Distraction (accommodates
  sources that are yet to evolve)

4
Exposure

• Exposure data are used to
• Identify activities that contribute to
  distraction-related crashes and incidents
• Calculate the risk of being involved in a crash
  or near-crash when engaging in an activity
• Identify which driving populations are engaging
  in distracting activities and under what
  circumstances
• Develop and evaluate countermeasures that target
  at-risk driver groups

5
What are drivers distracted by?

• Distraction exposure research is still in its
  infancy
• Majority of studies have focused on mobile phone
  use
• Around 60 of drivers use a mobile phone
• Around one third of these drivers use a hand-held
  phone exclusively
• More than half of young and middle-age drivers
  read and send SMS when driving
• Other activities
• 100 of drivers manipulate vehicle controls
• 90 of drivers manipulate audio system controls
• 75 of drivers eat or drink
• 7 of drivers smoke
• 6 of drivers distracted by external
  events/objects
• Stutts et al. (2003 2005)

6
Who is distracted?

• Driver engagement in potentially distracting
  activities is most common among drivers who are
• Young
• Inexperienced
• Travel mainly in urban areas
• Have high annual mileage rates
• e.g. mobile phone use
• Young (18-25 yrs) - 70
• Middle-age (26-54 yrs) 70
• Older (55 yrs) - 28 2007 Victorian data

7
Impact on Driving

• Research has focused mainly on impact of
  technologies (e.g. mobile phone, navigation
  systems)
• Little is known about the relative impact on
  driving performance of different driver actions
  (e.g. dialling, talking, texting) for a given
  source of distraction (e.g. mobile phone)
• Little known about impact of everyday
  distractions
• Almost nothing is known about distraction
  potential of driving- related tasks (e.g.
  changing gears, checking speedo)
• Even less is known about the potentially positive
  effects that some sources of distraction might
  have on driving performance (e.g. increasing
  alertness)

8
Impact - In-Vehicle Distraction

• Degraded lane keeping
• Degraded speed control
• Increased reaction time
• Missed traffic signals
• Shorter/longer following distances
• Accept unsafe gaps
• Increased mental workload
• Reduced situation awareness
• Visual scanning

9
Impact - External Distraction

• Four categories
• built roadway
• situational entities
• natural environment
• built environment
• Chapter 15 expands on these categories
• Case Study Billboards
• Billboards affect hazard detection
• Moving (video) billboards more distracting than
  static
• Street level signs more distracting than raised
  signs
• Higher crash rates associated with electronic
  billboards, billboards at intersections and long
  road stretches

10
Moderating Factors

• Amount of time distracted (exposure)
• System design
• Task demands/complexity (driving secondary
  tasks)
• Task practice
• Age and experience
• Driver state (fatigued, drowsy, inebriated)
• Self-regulation strategies

11
Role of Distraction in Crashes

• Crashes deriving from distraction often leave no
  trace
• Estimates vary due to differences in definitions
  of distraction, data collection methods, and
  classification schemes
• Findings from the analysis of Police-reported
  crashes suggest that driver distraction is a
  contributing factor in between 10 to 12 percent
  of all crashes
• Data from the US 100-car naturalistic driving
  study suggest that distraction from secondary
  tasks is a contributing factor in up to 23
  percent of crashes and near-crashes
• There is good reason to believe that these
  estimates underestimate the true scale of the
  problem

12
Role of Distraction in Crashes

• Distraction appears to be largely associated
  with
• rear-end crashes
• same travel-way/same direction crashes
• single-vehicle crashes
• crashes occurring at night

13
Crash Risk

• Secondary Tasks Odds Ratio PAR
• Reaching for a moving object 8.8 1.1
• Insect in vehicle 6.4 0.4
• Looking at external object 3.7 0.9
• Reading 3.4 2.9
• Applying makeup 3.1 1.4
• Dialing hand-held device 2.8 3.6
• Inserting/retrieving CD 2.3 0.2
• Eating 1.6 2.2
• Reaching for non-moving object 1.4 1.2
• Talking/listening to a hand-held device 1.3 3.6
• Drinking from open container 1.0 0.0
• Other personal hygiene 0.7 n/a
• Adjusting radio 0.6 n/a
• Passenger in adjacent seat 0.5 n/a
• Passenger in rear seat 0.4 n/a
• Combing hair 0.4 n/a
• Child in rear seat 0.3 n/a

Result was statistically significant from an
odds ratio of one
Adapted from Klauer et al. (2006)
14
Crash Risk

• According to the 100-car study, the tasks with
  the greatest population attributable risk
  percentages are
• dialling hand-held device
• talking/listening to hand-held devices
• reading
• eating
• personal grooming
• reaching for non-moving object
• reaching for moving object
• looking at external object
• These sources of distraction, and particularly
  those highlighted in red, should be a primary
  focus of distraction countermeasure development