title: Nighttime observations of safety belt use: an evaluation of California's primary law.
abstract: OBJECTIVE
  An analysis was conducted to determine what effect California's change to a primary safety belt law had on safety belt use among nighttime weekend drivers.
  
  
  METHODS
  Observations of 18,469 drivers in 2 California communities were made during voluntary roadside surveys conducted every other Friday and Saturday night from 9 PM to 2 AM for 4 years.
  
  
  RESULTS
  Rates of safety belt use rose from 73.0% to 95.6% (P < .0005). For drivers with blood alcohol concentrations of 0.10 or higher, rates rose from 53.4% to 92.1% (P < .0005).
  
  
  CONCLUSIONS
  Because substantial improvement in safety belt use was seen even in a group of high-risk drivers, the injury reduction benefits of this law may be high.
authors.affiliation: Pacific Institute for Research and Evaluation, Bethesda, MD. 20814, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Lange
authors.forename: R B
authors.initials: RB
authors.lastname: Voas
mesh_terms: D000063:Accidents, Traffic / Q000331:legislation & jurisprudence / Q000517:prevention & control; D000428:Alcohol Drinking / Q000517:prevention & control; D002140:California; D006801:Humans; D016015:Logistic Models; D012622:Seat Belts / Q000331:legislation & jurisprudence* / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires; D013997:Time Factors