The parents of a 13-year-old boy who was killed in a school bus crash say they are still anxious about the road.

An inquest into the death Tomas Ryan-Vig heard the teenager died of multiple injuries after the school bus he was travelling in collided with a tractor and trailer last May, on the B4100 near Bicester.

Tomas Ryan-Vig Edward Rainbow, a manager for Jeffs Coaches, told the hearing, at Northampton General Hospital, that he had been driving 48 children home from Blessed George Napier School, in Banbury, when the accident happened.

He said: "The trailer was over the white lines. I did feel it was going too fast for a tractor and trailer.

"I was far over to the left -- the coach scraped down the side of the bridge. I could not get any further over."

In a statement read out by Coroner Anne Pember, witness Mark Jones, of Round Close, Adderbury, said: "The tractor was hit by the side of the coach, which I can only describe as an explosion. It was unfortunate two big vehicles met on the bridge."

Tractor driver Benjamin Andrews, of Chester Avenue, Bettersden, Ashford, Kent, said in a statement that he had travelled the road several times that day and had a good idea of its layout.

He recalled travelling at a reasonable speed as the tractor could not travel at high speeds.

Accident investigator Pc Brian Johnson said the tractor's tachograph showed it had travelled at up to 37mph. He believed the coach had been travelling in its own lane when the vehicles collided.

He said both drivers would have had about two seconds to react before the collision.

Mrs Pember recorded a verdict of accidental death. After the hearing Tomas' mother, Helen Ryan, said she had grave concerns about the road but hoped the proposed safety measures would improve it.

She said: "Our daughter is travelling the same bus route and that's why we are so concerned about it.

"It's just a really terrible bend with no room for any mistakes whatsoever. In my opinion the speed limit should be brought down."

Likely improvements include more signs -- including a solar or wind power activated sign -- improved road markings and warning signs.

Mr Andrews is due to face a charge of driving without due care and attention. A date has not been set for the hearing.