title: Nonprogression through graduated driver licensing: characteristics, traffic offending, and reasons for nonprogression.
abstract: OBJECTIVE
  In a graduated driver license environment, (1) compare nonprogressors with progressors in terms of prelearner license sociodemographic and behavioral factors, (2) determine whether nonprogressors were more likely to have had a traffic offense than progressors, and (3) determine why nonprogressors chose not to progress.
  
  
  METHODS
  Our study population was that of the New Zealand Drivers Study (NZDS), a prospective cohort study of newly licensed drivers designed to explore the relationship between a comprehensive range of driving and traffic safety related factors and subsequent traffic crashes and convictions among newly licensed drivers. Nonprogressors, those who had not progressed from a learner to a restricted license 2 years after being eligible to do so, were compared with progressors in terms of their sociodemographic, behavioral characteristics, and traffic offense outcomes.
  
  
  RESULTS
  Nonprogressors represented 38 percent of the cohort and had different sociodemographic and behavioral profiles than progressors. A delay in progression was associated with reduced risk of being a traffic offender. The primary reasons reported for nonprogression were too lazy or busy or limited access to the means to drive.
  
  
  CONCLUSIONS
  Before restricting how long a novice driver can hold a learner license, as has been suggested by the Ministry of Transport, consideration should be given to the potential increased risk of offending once unsupervised driving is permitted.
authors.affiliation: Injury Prevention Research Unit, Department of Preventive and Social Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand. john.langley@otago.ac.nz
authors.forename: John
authors.initials: J
authors.lastname: Langley
authors.forename: Dorothy
authors.initials: D
authors.lastname: Begg
authors.forename: Rebecca
authors.initials: R
authors.lastname: Brookland
authors.forename: Ari
authors.initials: A
authors.lastname: Samaranayaka
authors.forename: Hannah
authors.initials: H
authors.lastname: Jordan
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Davie
mesh_terms: D000063:Accidents, Traffic / Q000706:statistics & numerical data; D000293:Adolescent; D001334:Automobile Driving / Q000331:legislation & jurisprudence* / Q000523:psychology; D005260:Female; D006801:Humans; D008004:Licensure / Q000706:statistics & numerical data*; D008297:Male; D009520:New Zealand; D011446:Prospective Studies; D018570:Risk Assessment; D012959:Socioeconomic Factors; D013997:Time Factors; D055815:Young Adult