Court: Court of Appeal
Citations: [1998] 1 WLR 1263; [1998] RTR 390; [1997] PIQR P526; [1997] CLY 3765
The case of Mansfield v Weetabix Ltd is a landmark Court of Appeal decision in English tort law concerning negligence and the standard of care expected of drivers who suffer sudden, unforeseen medical conditions that impair their ability to drive. The ruling in this case clarified how the law treats drivers who are genuinely unaware of an incapacitating illness at the time of an accident, distinguishing civil liability from criminal responsibility. The case also distinguished itself from the earlier decision in Roberts v Ramsbottom [1980], which dealt with a driver who had some awareness of his illness before an accident.
Facts of Mansfield v Weetabix Ltd
In Mansfield v Weetabix Ltd, the defendant, Mr Mansfield, was employed as a driver by Weetabix Ltd. Unknown to him and his employer, he suffered from malignant insulinoma—a rare medical condition that can cause sudden drops in blood sugar, known as hypoglycaemic episodes. These episodes severely impair cognitive and motor functions, often without warning.
On the day in question, Mr Mansfield was driving a lorry for Weetabix when he suddenly entered a hypoglycaemic state. During this period, his driving became erratic, and he lost control of the vehicle. This resulted in a collision with the claimant’s shop, causing significant property damage. Crucially, Mr Mansfield was not aware at any time during his impaired driving that his ability to control the vehicle was compromised. Neither he nor his employer knew about the condition before the accident.
The claimant sued Weetabix Ltd for negligence, arguing that the company was liable for the damages caused by their employee’s negligent driving.
Legal Issues
The principal issue before the Court of Appeal in Mansfield v Weetabix Ltd was the determination of the standard of care to be applied to a driver who suffers a sudden, incapacitating illness of which they are unaware. More specifically:
- Should the driver be held to the standard of a reasonably competent driver without any illness, even if the illness causes an impairment that is unforeseeable?
- Or should the driver’s unknown medical condition be taken into account when assessing whether the driver breached the duty of care owed to others on the road?
This issue raised important questions about how the law balances the interests of public safety with fairness to drivers who suffer sudden medical incapacities.
Mansfield v Weetabix Ltd Judgement
The Court of Appeal, in Mansfield v Weetabix Ltd, allowed the appeal in favour of the defendant employer, Weetabix Ltd. The court held that the driver’s medical condition must be taken into consideration when determining the applicable standard of care. Since Mr Mansfield was unaware of his malignant insulinoma and the resulting hypoglycaemic episode, he could not be held to the same standard as a reasonably competent driver who was fully aware and healthy.
The Court emphasised that this was a civil case of negligence, not a criminal case where strict liability might apply. It ruled that the standard of care should be modified to reflect a “reasonable person who has the illness but is unaware of it.” Therefore, Mr Mansfield’s driving conduct must be judged against what a reasonable driver in his actual position—suffering from the same condition and ignorance—would have done.
Accordingly, the court concluded that Weetabix Ltd was not negligent because their employee had not failed to meet this modified standard of care. The accident was caused by an unforeseeable medical condition, and no breach of duty could be attributed to Mr Mansfield or his employer.
Reasoning in Mansfield v Weetabix Ltd
The Court’s reasoning in Mansfield v Weetabix Ltd is significant for several reasons:
- Subjective Awareness as Part of the Standard of Care: The court introduced a limited subjective element to the standard of care in negligence. This means that when assessing whether a person was negligent, the court should consider the person’s actual awareness of their medical condition. If the driver genuinely lacked knowledge of the condition causing their impairment, this ignorance affects the standard to which they are held.
- Distinction Between Civil and Criminal Liability: The court distinguished the approach to liability in civil negligence from that in criminal law. In criminal prosecutions, such as dangerous driving offences, strict liability or a higher standard might apply, and a driver could be held liable regardless of awareness. However, negligence in civil law requires a fault-based inquiry, including consideration of what the driver knew or ought to have known.
- Avoidance of Strict Liability in Negligence: Imposing a strict liability standard for unforeseen medical conditions in negligence would be unfair and contrary to principle. The ruling in Mansfield v Weetabix Ltd avoids this by recognising that a driver who unknowingly suffers a sudden incapacity cannot be deemed negligent for something beyond their control.
- Precedential Impact: The case reaffirmed the position that drivers have a duty to avoid driving if they know or ought to know they are impaired. However, it also carved out an exception where the impairment is truly unforeseeable and unknown to the driver.
Relationship with Roberts v Ramsbottom
In delivering its judgement, the Court of Appeal in Mansfield v Weetabix Ltd explicitly addressed the earlier case of Roberts v Ramsbottom [1980] 1 WLR 823. In Roberts, the defendant driver suffered a stroke while driving but was aware before losing full control that something was wrong. The court held him liable for negligence because he continued driving despite experiencing warning signs of his incapacity.
The Mansfield court disapproved of but did not overrule Roberts. It explained that the key distinction between the two cases lies in the driver’s awareness. In Mansfield, the driver had no reason to believe he was ill and had lost the ability to appreciate that he was out of control. In Roberts, by contrast, the driver had some awareness of his deteriorating condition but failed to act responsibly.
Given that Mansfield v Weetabix Ltd was a Court of Appeal decision and Roberts was a High Court case, the former has greater precedential weight. The Court advised that where there is doubt, Mansfield v Weetabix Ltd should be applied.
Conclusion
The case of Mansfield v Weetabix Ltd remains a foundational authority in English law on how to assess negligence where a driver suffers a sudden, unknown medical condition that affects driving ability. The Court of Appeal’s ruling recognises the complexity of imposing liability in such situations and introduces a flexible standard of care based on the driver’s actual knowledge and condition.
By distinguishing this case from Roberts v Ramsbottom, the court refined the law on when a driver’s illness and awareness should influence negligence liability. The practical effect of Mansfield v Weetabix Ltd is that drivers and employers may avoid liability when an accident is caused by a sudden medical incapacity that the driver could not reasonably have foreseen or prevented.
