A special court of three judges, led by Chief Justice Sundaresh Menon, yesterday overthrew a longstanding sentencing practice of the courts to typically impose fines, rather than jail, for causing death by negligent driving.
Though cases rarely draw prison time, the CJ said judges should no longer operate on the premise that a fine is the default sentence.
"It is important to signal to other drivers that they must be mindful of the terrible risks they take upon themselves and other road users when they drive when not fit to do so," said CJ Menon.
The court will issue detailed written grounds at a later date.
It made the ruling as it allowed the prosecution's appeal for a four-week jail term for 27-year- old Hue An Li, a sleep-deprived driver who crashed her car into a lorry carrying foreign workers in March last year.
The impact caused all nine workers seated in the back to be flung out, killing one of them.
In September, Hue, a casino surveillance officer, pleaded guilty to causing death by a negligent act and was fined the maximum $10,000 and banned from driving for five years.
The prosecution appealed to the High Court, arguing that she should be jailed for her "gross negligence" in driving even though she had not slept in 24 hours. After a 12-hour shift, she stayed out with friends, and was going home when the accident happened.
The offence carries a jail term of up to two years, or a fine, or both, but the courts have generally imposed fines in most cases. In 1993, then Chief Justice Yong Pung How ruled that if death were caused by a negligent act, a fine would usually suffice.
In Hue's case, in explaining why he had given her a fine instead of jail, the district judge cited the 2012 case of Mr Ng Jui Chuan, who fell asleep at the wheel and hit an elderly couple in Upper Thomson Road in 2009.
Mr Ng's $9,500 fine was upheld by a High Court judge, who said that driving when one is tired or sleepy is not an offence, unless it were proved that the driver knew he was likely to fall asleep, but continued to drive.
Yesterday, CJ Menon said the 1993 and 2012 cases had to be viewed with caution and that the sentencing precedents were "unreliable" without taking into context the judges' comments.
CJ Menon said Mr Ng's case should not be seen as an appropriate sentencing precedent as the remarks of the High Court were in the context of drawing the line between a rash and negligent act, rather than about sentencing for the latter. He noted that the law was redrafted in 2008, after which there was no basis to continue with the premise that the default sentence for causing death by negligence is a fine.