Two men were killed when a hedge acting like a “steeplechase fence” launched a car over the central barrier of a dual carriageway, an inquest heard this week.

The driver of the car, Aldershot man Ivor Lunn, lost control on the eastbound side of the A303 near Micheldever before hitting the hedge, which threw it over crash barriers directly into the path of an oncoming vehicle.

The drivers of both cars were instantly killed.

The accident could now lead to major changes around Britain’s trunk roads, leading to miles of existing hedges being torn out.

The incident happened just after 4pm on July 24 this year, near the junction with the M3 motorway, Basingstoke coroner’s court heard on Tuesday this week.

Witnesses told coroner Andrew Bradley how Mr Lunn, 41, an Army contracts worker who was driving home to Arnhem Barracks, seemed to drift off to the left-hand side of the dual carriageway in an apparent lapse of concentration.

Mr Lunn’s car, a 2005 silver Peugeot 206, then seemed to steer sharply back into the carriageway, careering across both lanes towards the central reservation, witnesses said.

As the car skidded towards crash barriers, it hit a low hawthorn hedge in front of the barrier, forcing the car over the central reservation and into the path of an oncoming Range Rover Freelander, driven by Colin Evans, a 54-year-old father from Andover.

Mr Lunn’s Peugeot was still in mid-air when the vehicles collided at high speed.

Witnesses described how the Peugeot twisted through the air, coming down directly on top of the driver’s side of the Range Rover.

Christopher Speed, who was driving home to Kent from Devon, told the inquest Mr Lunn’s car went towards the central reservation at 45 degrees, diagonally across the road.

“The vegetation in front of the barrier lifted him over,” he said. “When it took off you could hear the engine screaming. I thought he went straight over because he went up so sharply and down so sharply. I saw it go straight over, straight into the windscreen of the car coming the other way.”

A driver on the other side of the road, following Mr Evans’s Range Rover, described how he saw a car swallow dive onto Mr Evans’s vehicle over the central reservation.

Jonathan Davis, who was driving home to Andover from Camberley, said he had to brake hard to avoid hitting the spinning Peugeot after the massive collision.

He got out of his car to help the occupants of the two vehicles, but it quickly became apparent that there was nothing that could be done to help either driver, he said.

Police crash investigator Pc David Whiting, said that the evidence suggested that Mr Lunn had drifted off to the side of the road through a lack of concentration or by a distraction in his car. However, none of the witnesses reported being aware of anything he was doing that was dangerous.

Pc Whiting added that if had not been for the low hawthorn hedge, Mr Lunn’s car would have hit the crash barrier and rebounded into the eastbound carriageway.

He added that a report produced for the inquest by the Transport Research Laboratory showed that road planners had no idea such a hedge could throw a car over safety barriers.

The crash was the first of its kind involving a hedge he had ever come across, he told the inquest.

Richard Follis, acting for Mr Evans’s family, said the “steeplechase effect” should be brought to the government’s attention. The current guidance on the protection of trees around roads had missed the point about keeping people safe, he said.

“Someone needs to look to see if the guidance needs to be changed,” Mr Follis said. “This is a section of the road where a containment barrier fails to contain and it had tragic consequences.”

Recording a verdict of accidental death for both Mr Evans and Mr Lunn, the coroner said he would inform the Department for Transport about the accident in an attempt to prevent such deaths from happening in the future.

Mr Bradley said that the accident had occurred due to an extraordinary set of circumstances.

Speaking after the verdict, Sergeant Wayne Voller, of Hampshire’s roads policing unit, said that the decision of the coroner to inform the Department for Transport could lead to major changes to miles of roads across Britain where hedges had been planted in front of crash barriers.

“If it had hit the barrier without the vegetation, we are almost certain it would have been redirected back into the carriageway,” he said.

“Mr Evans would not have been involved at all and hopefully Mr Lunn would not have been seriously injured. In all probability they both would have been alive today.”

In a statement given by their solicitor, Mr Evans’ family called for action.

“Colin was a wonderful son, a loving husband and a fantastic father. He and his wife had 32 terrific years together,” the statement said. “This was a tragic accident and something should now be done so it does not happen to someone else.”

Mr Lunn was a member of Holy Trinity Church in Victoria Road, Aldershot. An online dedication book has been set up in his memory on a website for churches in the area.