SINGAPORE - A man who caused the death of a rider on a power-assisted bicycle by negligence was sentenced to two weeks' jail and banned from driving for three years on Tuesday.

Machinist Cheng Kim Leng, 56, who pleaded guilty, was behind the wheel of a van when he failed to keep a proper lookout while turning out of the slip road from Sin Ming Avenue into Marymount Road on April 22 this year.

He hit the back of security guard Ridwan Ibrahim, 55, who was travelling on the left lane along Marymount Road, causing his death.

The court heard that Cheng was emerging from the slip road into Marymount Road when he suddenly noticed Mr Ridwan about 3m away on the leftmost lane.

But he was unable to stop in time and hit the rider.

Mr Ridwan suffered severe injuries and died more than an hour later in Tan Tock Seng Hospital.

Deputy Public Prosecutor Jeremy Lua had sought a jail term of two to four weeks as well as three years' disqualification, citing aggravating factors. He said while Cheng had slowed down for oncoming traffic, he did not stop to do so.

He said the accident was solely caused by Cheng's failure to keep a proper lookout and stop at the road to check if there was any vehicle on his left as well as his right.

"Given that the weather was fair on that day, there was no reason why the accused would not have spotted the deceased had he kept a proper lookout," he said.

Cheng's lawyer, Mr Loh Lin Kok, said the father of two was going to Ang Mo Kio to buy medicinal herbs for his 84-year-old mother. He said Cheng did not stop as he was momentarily inattentive.

He successfully applied for Cheng's sentence to be deferred for three weeks. District Judge Salina Ishak ordered that Cheng top up $5,000 for his current $10,000 bail and surrender his passport.

Cheng could have been jailed for up to two years and/or fined for causing death by doing a negligent act.