title: Real-world effects of using a phone while driving on lateral and longitudinal control of vehicles.
abstract: BACKGROUND
  Technologies able to augment human communication, such as smartphones, are increasingly present during all daily activities. Their use while driving, in particular, is of great potential concern, because of the high risk that distraction poses during this activity. Current countermeasures to distraction from phone use are considerably different across countries and not always widely accepted/adopted by the drivers.
  
  
  METHODS
  This study utilized naturalistic driving data collected from 108 drivers in the Integrated Vehicle-Based Safety Systems (IVBSS) program in 2009 and 2010 to assess the extent to which using a phone changes lateral or longitudinal control of a vehicle. The IVBSS study included drivers from three age groups: 20–30 (younger), 40–50 (middle-aged), and 60–70 (older).
  
  
  RESULTS
  Results from this study show that younger drivers are more likely to use a phone while driving than older and middle-aged drivers. Furthermore, younger drivers exhibited smaller safety margins while using a phone. Nevertheless, younger drivers did not experience more severe lateral/longitudinal threats than older and middle-aged drivers, probably because of faster reaction times. While manipulating the phone (i.e., dialing, texting), drivers exhibited larger lateral safety margins and experienced less severe lateral threats than while conversing on the phone. Finally, longitudinal threats were more critical soon after phone interaction, suggesting that drivers terminate phone interactions when driving becomes more demanding.
  
  
  CONCLUSIONS
  These findings suggest that drivers are aware of the potential negative effect of phone use on their safety. This awareness guides their decision to engage/disengage in phone use and to increase safety margins (self-regulation). This compensatory behavior may be a natural countermeasure to distraction that is hard to measure in controlled studies. Practical Applications: Intelligent systems able to amplify this natural compensatory behavior may become a widely accepted/adopted countermeasure to the potential distraction from phone operation while driving.
authors.affiliation: Division of Vehicle Safety, Chalmers University of Technology, Lindholmspiren 3, S-417 56, Gothenburg, Sweden. Electronic address: marco.dozza@chalmers.se.
authors.forename: Marco
authors.initials: M
authors.lastname: Dozza
authors.affiliation: University of Michigan Transportation Research Institute, 2901 Baxter Rd, Ann Arbor, MI 48109, USA.
authors.forename: Carol A C
authors.initials: CA
authors.lastname: Flannagan
authors.affiliation: University of Michigan Transportation Research Institute, 2901 Baxter Rd, Ann Arbor, MI 48109, USA.
authors.forename: James R
authors.initials: JR
authors.lastname: Sayer
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001288:Attention; D001334:Automobile Driving / Q000523:psychology* / Q000706:statistics & numerical data; D001364:Awareness; D040421:Cell Phone; D003142:Communication; D003617:Dangerous Behavior; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance; D011930:Reaction Time; D012107:Research Design; D012306:Risk; D012449:Safety; D000068997:Smartphone; D060145:Text Messaging; D055815:Young Adult
keywords: Age; Distraction; Driver behavior; Naturalistic data; Traffic safety