Last night Arthur and Linda Allen turned out the light in their son's bedroom for the first time since he was killed in a motorcycle accident 19 months ago.

David, 16, left the light on in his room when he went out on his moped, before he crashed into a barrier across a cyclepath next to the Eastern Bypass at Littlemore, Oxford.

Mr and Mrs Allen had not been able to bear to turn out the bulb until yesterday, after Oxfordshire coroner Nicholas Gardiner gave them some degree of closure as he recorded a verdict of accidental death.

"We kept it on since he died because we found it too hard to swtich it off," Mrs Allen said after the inquest. "Now I can turn it off."

The couple were also planning to burn their son's leather motorcycling jacket and bury the ashes under a holly bush in their back garden.

David, of Spencer Crescent, Rose Hill, died on November 20, 2004. The inquest was told that David was riding along the cycle path towards Littlemore at about 10pm, after a trip to Tesco in Cowley.

Witness Maykel Galli, said he was about 20m past the barrier when he heard a loud noise behind him and saw the bike skidding along Long Lane. Paramedics tried to save David, but he was pronounced dead at Oxford's John Radcliffe Hospital. Pathologist Dr David Davies concluded that he died of a skull fracture and brain damage.

Pc Geoffrey Chambers, of Thames Valley's collision investigation unit, said the moped's front tyre was over-inflated and the rear one was under-inflated.

He also found the back brake pads were not working, but he could not explain why David, who he thought was travelling at between 28mph and 34mph at the time of the crash, had failed to go through the 1.3m-wide opening for cyclists next to the barrier.

However, Mr Allen disputed Pc Chambers' conclusion that the barrier could be clearly seen from 75m away.

He said: "It was a bit drizzly at the time, and coming towards Littlemore, you cannot see the gate very clearly at all. The street light near to the barrier is hidden by a tree."

Mr and Mrs Allen fear there will be another tragedy if the barrier, which signals the end of the cycle path and the start of Long Lane in Littlemore, is not removed and replaced by bollards. The couple are planning to run a moped rally from Scotland to Oxford to raise money for the trauma unit at the John Radcliffe hospital.