title: Sleep-related vehicle crashes on low speed roads.
abstract: BACKGROUND
  Very little is known about the characteristics of sleep related (SR) crashes occurring on low speed roads compared with current understanding of the role of sleep in crashes occurring on high speed roads e.g. motorways. To address this gap, analyses were undertaken to identify the differences and similarities between (1) SR crashes occurring on roads with low (≤60km/h) and high (≥100km/h) speed limits, and (2) SR crashes and not-SR crashes occurring on roads with low speed limits.
  
  
  METHODS
  Police reports of all crashes occurring on low and high speed roads over a ten year period between 2000 and 2009 were examined for Queensland, Australia. Attending police officers identified all crash attributes, including 'fatigue/fell asleep', which indicates that the police believe the crash to have a causal factor relating to falling asleep, sleepiness due to sleep loss, time of day, or fatigue. Driver or rider involvement in crashes was classified as SR or not-SR. All crash-associated variables were compared using Chi-square tests (Cramer's V=effect size). A series of logistic regression was performed, with driver and crash characteristics as predictors of crash category. A conservative alpha level of 0.001 determined statistical significance.
  
  
  RESULTS
  There were 440,855 drivers or riders involved in a crash during this time; 6923 (1.6%) were attributed as SR. SR crashes on low speed roads have similar characteristics to those on high speed roads with young (16-24y) males consistently over represented. SR crashes on low speed roads are noticeably different to not-SR crashes in the same speed zone in that male and young novice drivers are over represented and outcomes are more severe. Of all the SR crashes identified, 41% occurred on low speed roads.
  
  
  CONCLUSIONS
  SR crashes are not confined to high speed roads. Low speed SR crashes warrant specific investigation because they occur in densely populated areas, exposing a greater number of people to risk and have more severe outcomes than not-SR crashes on the same low speed roads.
authors.affiliation: Queensland University of Technology (QUT), Centre for Accident Research and Road Safety - Queensland (CARRS-Q), 130 Victoria Park Road, Kelvin Grove, QLD, Australia. Electronic address: A.J.Filtness@lboro.ac.uk.
authors.forename: A J
authors.initials: AJ
authors.lastname: Filtness
authors.affiliation: Queensland University of Technology (QUT), Centre for Accident Research and Road Safety - Queensland (CARRS-Q), 130 Victoria Park Road, Kelvin Grove, QLD, Australia.
authors.forename: K A
authors.initials: KA
authors.lastname: Armstrong
authors.affiliation: Queensland University of Technology (QUT), Centre for Accident Research and Road Safety - Queensland (CARRS-Q), 130 Victoria Park Road, Kelvin Grove, QLD, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Watson
authors.affiliation: Queensland University of Technology (QUT), Centre for Accident Research and Road Safety - Queensland (CARRS-Q), 130 Victoria Park Road, Kelvin Grove, QLD, Australia.
authors.forename: S S
authors.initials: SS
authors.lastname: Smith
mesh_terms: D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D000328:Adult; D000368:Aged; D001315:Australia; D001334:Automobile Driving / Q000523:psychology / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011156:Population Density; D012890:Sleep; D012894:Sleep Stages; D012893:Sleep Wake Disorders / Q000150:complications* / Q000523:psychology; D055815:Young Adult
keywords: Driver drowsiness; Driver fatigue; Driver sleepiness; Police data; Road crash