Traffic accidents caused by heavy vehicles and buses have become more frequent over the years, causing concern over road safety and the driving behaviour of drivers of such vehicles.

The Singapore Traffic Police's annual report, released in February this year, showed that fatalities caused by road accidents involving heavy vehicles in 2013 increased by 37.5 per cent from the previous year. The number rose from 32 cases in 2012 to 44 cases in 2013.

We take a look at five road accidents involving heavy vehicles and buses that have garnered public and media attention over the year.

1. Teenager brain-dead after being run over by lorry

An 18-year-old boy, Tien Kang Fan, was run over by a lorry in Sin Ming Avenue and was left brain dead after emergency brain surgery on May 5, 2014.

The teenager had bade farewell to his father after leaving the house at 7am to catch his bus to Ngee Ann Polytechnic, where he was a first-year student in logistics and supply chain management.

Mr Tien Yoon Seong, Kang Fan's father, was notified of his son's accident at 10.40am, when the boy was already undergoing a brain operation at Tan Tock Seng Hospital.

Kang Fan's family decided to take the second of their three sons off life support on May 7.

On the same day, another pedestrian, 72-year-old Khoo Thuan Kheng, was also hit by the same lorry when she was returning home after her regular morning exercise. She suffered serious fractures and died the next day.

Investigations are still ongoing with the help of the 55-year-old Singaporean lorry driver.

2. Three-year-old boy killed by bus at cemetery

A three-year-old boy, Kryshan Nirmal Kumar, was fatally run over by a private bus at a cemetery in December last year. He was attending a funeral at a Christian cemetery in Choa Chu Kang with his mother, Madam Jaiyesthri Ramasamy, and older brother.

The bus driver, Mr Ng Yam Bak, who ferried the family and other relatives to the funeral, was driving off when he ran over Kryshan.

At the coroner's inquiry last week, Mr Ng said that he was "misdirected" by the cries of an eight-year-old boy in the bus whose parents had left him sleeping. He also did not see anyone standing in front of the bus because Madam Jaiyesthri was squatting down in the blind spot of the bus to tie the shoelaces of her older child.

The coroner had declared the accident as a "tragic confluence of several events, all occurring at the same time".

Mr Ng has yet to be sentenced.

3. Elderly woman run over by tipper truck

A retired midwife, 81-year-old Chin Siat Keow, was run over by a tipper truck near the junction of Henderson Road and Jalan Bukit Merah on Nov 30, 2013 at about 12.30pm. She was lugging a stack of cardboard sheets across the road and was just metres away from the pavement when the accident occurred.

She died from multiple injuries in hospital, including fractures and injuries to her pelvis and lumbar spine, about nine hours after the accident.

Taxi driver Leong Yin Fatt, 47, was two cars behind the truck and said that while he did not witness the collision, he saw Madam Chin's body lying on the ground and emerging from under the middle of the truck.

State Coroner Marvin Bay, during the coroner's inquiry on May 20 this year, stated that the 49-year-old truck driver Toh Siong Thoh should have checked for the 1.47m-tall elderly woman before moving his 2.2m vehicle. However, he concluded that both parties contributed to the unfortunate confluence of events.

It is not known if Mr Toh will be charged.

4. Wife of NUS don killed after being pinned under bus

Zhang Hui Rui, a 42-year-old housewife, was killed after being pinned under a bus and dragged for 10.2m on April 23, 2013 at around 7.40am. The SBS Transit double-decker bus had failed to give way to her when she was walking on a pedestrian crossing at the junction of Clementi Avenue 3 and Commonwealth Avenue West.

Zhang was the wife of Associate Professor Gong Jiangbin, who lectures at the National University of Singapore.

She suffered severe injuries, including skeletal fractures, and was pronounced dead at the scene.

The former bus driver, 48-year-old Chan Mun Hing, was sentenced on March 24 this year to three weeks' jail and was banned from driving for five years.

5. Cycling brothers knocked down by cement-mixer truck

Two young cyclists, Nigel Yap Yew Cheong, 13, and his brother Donavan Yap Teck Siong, seven, who was riding pillion, were hit by a cement-mixer truck on Jan 28, 2013.

The brothers were cycling along Tampines Street 45 at 5.43pm when the vehicle driver, Munir Mohd Naim, made a left turn from Tampines Avenue 9 into Tampines Street 45 and collided into them. His rear left tyre had run over the pair. Eyewitnesses said that the 57-year-old had driven to the junction and made a left turn without stopping.

The brothers were pronounced dead at the scene by a paramedic.

On Jan 24 this year, one year after the accident, the court sentenced the cement-mixer driver to two weeks' jail and banned him from driving all vehicles for five years upon his release.