Fatal distraction: a case series of fatal fall-asleep road accidents and their medicolegal outcomes

Anup V Desai, Ronald R Grunstein, Elizabeth Ellis and John R Wheatley
Med J Aust 2003; 178 (8): 396-399. || doi: 10.5694/j.1326-5377.2003.tb05258.x
Published online: 21 April 2003


  • Obstructive sleep apnoea is associated with an increased risk of sleep-related motor vehicle accidents.

  • Seven recent legal cases of fatal motor vehicle accidents on NSW roads are presented, where the driver who caused the accident was suffering from an unrecognised or under-treated sleep disorder.

  • The legal outcomes in these cases were variable: some of the drivers have been acquitted and others have been jailed. All remained licensed to drive immediately after their accidents.

  • In some of the cases, the driver was cleared of any culpable driving offence because of a defence of sleepiness or a sleep attack without warning ("Jiminez defence"). This appears at odds with current medical research and legal opinion in other countries.

  • More research is needed to understand the relation between sleep disorders and awareness of sleepiness.

  • Medical practitioners need to be aware of current advice and guidelines with respect to obstructive sleep apnoea and driving.

Driver fatigue or sleepiness is a widespread and serious problem within our society. Studies have attributed more than 20% of road accidents to driver sleepiness.1,2 Obstructive sleep apnoea (OSA), a common sleep disorder affecting about 25% of middle-aged men,3 is an important cause of driver fatigue. Drivers with OSA show a 2–7-times increased risk of motor vehicle accidents (MVAs) compared with drivers who do not have OSA.4,5

In 1992, in Jiminez v The Queen,6 the High Court of Australia ruled that just because an accident is caused by a driver falling asleep does not mean that the driver had sufficient warning to stop driving. Because sleep, in this view, is involuntary, and people cannot be charged for involuntary acts, the "Jiminez defence" potentially enables many drivers to escape blame in the case of fall-asleep MVAs.

We describe seven fall-asleep fatality-associated MVAs that have occurred on New South Wales roads since 1995 in the setting of unrecognised or undertreated sleep disorders.


These cases (Box 1) represent consecutive referrals to the sleep disorders centres at Royal Prince Alfred Hospital (6 patients) and Westmead Hospital (1 patient), Sydney, for medicolegal opinions in fall-asleep MVAs where the driver who caused the accident survived. Drivers were aged between 30 and 60 years at the time of their MVAs. Five of the cases involved commercial drivers. For each case, police investigations did not identify the weather, road environment or vehicle mechanical condition as significant contributors to the MVAs. The contribution of alcohol was ruled out by breath or blood tests. Each subject underwent investigations (Box 2) to identify sleep disorders that might have contributed to the MVA. Each driver had at least one overnight sleep study. In six of the cases, an objective measurement of daytime sleepiness was also performed.


In each of these seven cases, the driver who caused the accident suffered from an unrecognised or undertreated sleep disorder. The nature of many of the accidents suggests inattention, with the vehicles crashing into the back of stationary cars or veering across the road, while showing little or no preventive action (eg, braking). This inattention could have causes other than the driver having fallen asleep. However, neurological clinical assessment or tests did not suggest neurological causes for any of the accidents. When taken together with the drivers' clinical histories and sleep investigations, we feel that each episode of inattention was most likely due to sleep or sleepiness. Although untreated sleep disorders could explain these possible episodes of sleep, inappropriate work and sleep schedules may also have contributed, especially for the commercial drivers.

The legal outcomes varied, despite similar circumstances. For instance, both A and G had known diagnoses of OSA and continued to drive while sleepy; A was no-billed, but G was jailed. As a second example, B had undiagnosed OSA, and a history of excessive daytime sleepiness, and was no-billed, whereas D also had undiagnosed OSA, denied awareness of excessive daytime sleepiness, and yet was jailed. These apparent judicial inconsistencies might relate to current difficulties in apportioning blame to OSA in fall-asleep MVAs. Although drivers with OSA as a group show increased sleepiness and driving accident risk, many individuals with OSA may be safe drivers.8 However, there are no clear clinical markers or laboratory tests that can identify which drivers with OSA are at higher or lower risk of causing an accident.9

The legal proceedings in cases A, B and C all considered the Jiminez defence. Legal opinion is divided on whether falling asleep at the wheel is always foreseeable or whether sleep can occur without warning. One view, still held by the Canadian and English courts, implies that ordinary people who fall asleep at the wheel are liable for their actions regardless of the circumstances. These judgements are predicated on the "prior fault" principle10 that there was a period of voluntary conduct before being asleep, when a person chose to take the risk of continuing to drive. This way of thinking was recently used in the United Kingdom to convict a driver who fell asleep at the wheel after driving while sleep deprived and caused an accident involving two trains, in which 10 people died.11 In contrast, in Jiminez v The Queen,6 the High Court of Australia found that falling asleep while driving could be considered an unexpected event.

The Jiminez defence appears to be at odds with current medical evidence. Three studies have shown that healthy people do not fall asleep without a significant awareness of sleepiness for some time before a fall-asleep episode.12-14 These data challenge the use of the Jiminez defence in cases such as C's. However, it is important to note that this research on awareness of sleepiness was conducted with healthy volunteers, not patients with sleep disorders. Patients with sleep disorders may not be as aware of impending sleep. For example, patients with OSA are often only aware of the severity of their sleepiness retrospectively (ie, after treatment of their OSA).15 Studies of perception of sleepiness before sleep onset are needed for other groups, especially for people with OSA.

Although some of the drivers used the defence of falling asleep suddenly without awareness, all were allowed to continue driving until after their trials. This appears dangerous and inconsistent. Recent legislative changes in NSW have removed some of the legal constraints on licence suspension that previously handicapped the RTA in managing fall-asleep MVAs.16 The Road Transport (Driving Licensing) Regulation 1999, enacted in 2001, gives the RTA explicit power to suspend a licence if a driver has fallen asleep or has lost consciousness and caused death or injury. The licence can be suspended regardless of whether the person has been prosecuted for an offence. The courts will only allow an appeal if the person can demonstrate that he or she is medically fit to have the licence renewed.

Healthcare practitioners have a duty of care to their patients to provide advice and treatment at the prevailing, acceptable standard. A driver presenting with symptoms suggestive of OSA should be warned of the dangers of driving. The driver should also be warned about the early signs of drowsiness and the necessity to immediately stop driving if these occur. Finally, the driver should be referred to a sleep medicine specialist for assessment and further investigation. For medicolegal reasons, practitioners should carefully note advice about driving in patient records.

Previous national regulatory guidelines have been too vague about the requirements for diagnosis of OSA and its implications for driving.17 A recent review by the Australian Sleep Association advises that the guidelines be updated to recommend that drivers proven to have OSA on polysomnography and who report or are shown to have excessive daytime sleepiness should not drive until treatment is effective.18 The review also recommends that periodic review is required to ensure adequate treatment is maintained and that patients who do not comply with treatment while continuing to drive should be reported to licensing authorities. Although these recommendations on review and reporting are explicit, there is no clear evidence that every driver with OSA, with or without pathological sleepiness, has an increased MVA risk.

Current national guidelines emphasise the responsibility of individuals to notify the relevant State or Territory drivers' licensing authority of medical conditions that may affect their ability to drive safely, to comply with medical advice regarding satisfactory treatment, and to not pose a public risk.17 When an individual will not take responsibility for himself or herself and puts lives at risk, the Australian Medical Association Code of Ethics acknowledges that a practitioner may have an obligation to breach patient confidentiality to report the situation to the appropriate authorities.19 In the case of drivers with OSA who report frequent sleepiness while driving or MVAs caused by inattention or sleepiness, we believe a practitioner is ethically compelled to report these drivers if they do not comply with treatment or follow-up. Legislation in all Australian States and Territories except Tasmania indemnifies medical practitioners in this situation.9

Legislators, medical practitioners and road safety specialists must recognise the changes in knowledge in this area and help to clarify the important medicolegal issues involved. In particular, the Jiminez defence, which is at odds with legal opinion in other countries and current medical evidence, should be rechallenged in the High Court or addressed through statute law at a State and Territory level, perhaps through the involvement of law reform commissions.

1: Case details of fall-asleep motor vehicle accidents (MVAs)

Case (diagnosis)

Overnight sleep study


Accident outcome

Legal outcome

Remained licensed?

A (OSA and PLMD)

With continuous positive airway pressure: AI, 30; AHI, 10; PLMI, 20

MWT20, 4.75 min

2 vehicles; 1 fatality; 2 others injured



B (OSA and UARS)

AI, 41; AHI, 10

MSLT, 9.4 min

2 vehicles; 1 fatality; 2 others injured



C (sleep deprivation)

AHI, 2.4; AHI, 1

MWT40, 40 min

4 vehicles; 5 fatalities; several others injured


Yes. Later withdrawn by RTA and then contested in court


AHI, 30

MWT40, 11 min

6 vehicles; 2 fatalities; 12 others injured

Found guilty; jailed


E (idiopathic hypersomnolence)

AHI, 0.4

MWT20, 8 min

5 vehicles; 1 fatality; 2 others injured

Pleaded guilty



AHI, 23

MSLT, 5.5 min

3 vehicles; 2 fatalities

Pleaded guilty; jailed



AHI, 17

Not performed

2 vehicles; 1 fatality

Found guilty; jailed

Yes. Later withdrawn by judge

OSA = Obstructive sleep apnoea. PLMD = Periodic limb movement disorder. RTA = Roads and Traffic Authority. UARS = Upper airway resistance syndrome. Normal ranges: apnoea–hypopnoea index (AHI), 0–5/hour; arousal index (AI), 0–10/hour; maintenance of wakefulness test 20 minute protocol (MWT20; sleep onset as the first occurrence of one epoch of any stage of sleep), 11–20 min; maintenance of wakefulness test 40 minute protocol (MWT40; sleep onset defined as three consecutive epochs of stage 1 sleep or any single epoch of another sleep stage), 19–40 min; multiple sleep latency test (MSLT), 10–20 min; periodic limb movement index (PLMI), 0–5/hour.

  • Anup V Desai1
  • Ronald R Grunstein2
  • Elizabeth Ellis3
  • John R Wheatley4

  • 1 Sleep Research Group, Woolcock Institute of Medical Research, Sydney, NSW.
  • 2 Faculty of Health Sciences, University of Sydney, Sydney.
  • 3 Department of Respiratory Medicine, Westmead Hospital, Sydney.



A D was funded in part by the Ann Woolcock Medical Research Scholarship from the Community Health and Anti-Tuberculosis Association (CHATA) and by a project grant from the Centre of National Research on Disability and Rehabilitation Medicine. R G was funded in part by a National Health and Medical Research Council Practitioner Fellowship.

Competing interests:

None identified.

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