The case of Hill v Baxter concerns the issue of automatism in driving in England and Wales without a diagnosed condition.

It sets out guidelines as to when the defence will apply, and when it will not and what jury instructions ("directions to the jury" or considerations by the magistrates) should be given to leave the defence open for them to find or deny, given appropriate medical evidence and the extent of wrongfulness involved in allowing the automatism to occur in many circumstances.

It was suggested (and accepted at first instance) that he was not fully conscious of what he was doing, and "that he was not capable of forming any intention as to his manner of driving.

As dangerous driving under the Road Traffic Act 1930 was an offence of strict liability, lack of mens rea would not be enough to exculpate him.

[3] The panel held that the jury or magistrates should be advised only a voluntary act or omission can qualify as an actus reus, however driving a substantial distance during the time of alleged transience of mind or consciousness would tend towards a finding of fact of some form of voluntary act, even if simply ignoring the signs of tiredness so being unfit to drive.