R v Hennigan [1971] 3 All ER 133

Death by dangerous driving – cause of accident – Road Traffic Act 1960 section 1


Hennigan drove at eighty miles per hour and hit the side of a car, driven by Lowe, who was emerging from a turning in a road. Lowe’s two passengers died from the collision. The accident happened at around 11.00pm in a restricted area. Hennigan was found guilty on two counts of causing death by dangerous driving, by a verdict of ten to two, fined £25 on each count and banned from driving for five and a half years. He appealed the conviction.


Had this been a civil claim, Lowe would have been substantially to blame because she was at fault when emerging from the minor road. The trial judge directed the jury to establish two elements. The first was whether the manner of Hennigan’s driving was dangerous or not and secondly that the dangerous driving had caused the accident in question. Importantly, the judge instructed the jury that a key determination was whether the dangerous driving was a ‘substantial cause’ of the death of the two passengers in Lowe’s car. The jury also sought further clarification from the judge as to the definition of ‘substantial’.


The court emphasised that there is nothing in the Road Traffic Act 1960 section 1 which requires driving to be the substantial or even major cause of an accident. Providing the driving was something more than de minimis, the legislation is in effect.  The court also supported the five and a half year driving suspension based on the fact that Hennigan was only twenty years old and already had been convicted for motoring offences.