title: Cellular phone use while driving at night.
abstract: OBJECTIVE
  Use of a cellular phone has been shown to negatively affect one's attention to the driving task, leading to an increase in crash risk. At any given daylight hour, about 6% of US drivers are actively talking on a hand-held cell phone. However, previous surveys have focused only on cell phone use during the day. Driving at night has been shown to be a riskier activity than driving during the day. The purpose of the current study was to assess the rate of hand-held cellular phone use while driving at night, using specialized night vision equipment.
  
  
  METHODS
  In 2006, two statewide direct observation survey waves of nighttime cellular phone use were conducted in Indiana utilizing specialized night vision equipment. Combined results of driver hand-held cellular phone use from both waves are presented in this manuscript.
  
  
  RESULTS
  The rates of nighttime cell phone use were similar to results found in previous daytime studies. The overall rate of nighttime hand-held cellular phone use was 5.8 +/- 0.6%. Cellular phone use was highest for females and for younger drivers. In fact, the highest rate observed during the study (of 11.9%) was for 16-to 29-year-old females.
  
  
  CONCLUSIONS
  The high level of cellular phone use found within the young age group, coupled with the increased crash risk associated with cellular phone use, nighttime driving, and for young drivers in general, suggests that this issue may become an important transportation-related concern.
authors.affiliation: Transportation Research Institute, UMTRI-Social and BehavioralAnalysis Division, The University of Michigan, Ann Arbor, Michigan 48109-2150, USA. jviv@umich.edu
authors.forename: Jonathon M
authors.initials: JM
authors.lastname: Vivoda
authors.forename: David W
authors.initials: DW
authors.lastname: Eby
authors.forename: Renée M
authors.initials: RM
authors.lastname: St Louis
authors.forename: Lidia P
authors.initials: LP
authors.lastname: Kostyniuk
mesh_terms: D000063:Accidents, Traffic / Q000517:prevention & control* / Q000706:statistics & numerical data; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001288:Attention; D001334:Automobile Driving / Q000523:psychology / Q000706:statistics & numerical data*; D040421:Cell Phone / Q000706:statistics & numerical data*; D002940:Circadian Rhythm; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007196:Indiana; D008297:Male; D008875:Middle Aged; D009755:Night Blindness / Q000175:diagnosis; D011336:Probability; D018570:Risk Assessment; D012449:Safety; D012737:Sex Factors