Teenagers left Wiltshire College in Chippenham in a stunned silence after a visit from the Safe Drive Stay Alive roadshow.

Nearly 450 students from Lackham were given a sobering dose of reality when they heard first-hand accounts from two mums who had lost their sons in car accidents.

The road safety campaign, coordinated by Wiltshire Fire & Rescue Service, shows a hard-hitting film recreating a crash, in a bid to make teenagers think twice before showing off in their first car.

Graphic footage, demonstrating what the police, paramedics and firefighters go through before casualties are sent to hospital, was accompanied by talks from family members left behind.

Many were unable to hold back tears after mum Clare Brixey told students about losing her son Ashley in a car crash at Limpley Stoke, near Bradford on Avon, ten years ago.

Ashley, 20, was a back-seat passenger in a car that landed upside down in a swimming pool after the driver, twice over the legal alcohol limit, lost control.

Both the driver and a passenger were thrown from the car and into the pool managing to escape, but Ashley was knocked unconscious and drowned.

When his parents were awoken at 3am by the doorbell they thought that Ashley had forgotten his key, but instead they found police standing at the door to inform them their son was dead.

Mrs Brixey said: “My personal testimony brings it closer to home and means it stays with them. It makes them realise that it could happen to them, they’re not invincible.”

Also speaking was Claire Barnett, of Semington, who also lost her 20-year-old son on Wiltshire’s roads.

James, who was an excelling landscape gardening design student at Lackham College, was killed in a motorbike accident in 2002 and has a tree planted in his memory at Lackham.

A car in front of him on the A361 had crashed into a telegraph pole and its drooping wires hit James at neck height, pulling him off the bike and crushing his windpipe.

“I wanted to do something after James died,” said Mrs Barnett.

“Every time I do this, my son and I save at least one life.

“If you see tears you know it has had a positive effect.”

Crash survivor Simon Johnstone, 35, spoke of how he was left brain-damaged and paralysed after crashing his Volvo on his return home to Chippenham from Northampton at the age of 18.

The impact when he collided with an oncoming car was 140mph and he had to learn to walk, talk and eat all over again.

After 10 years of intensive surgery and rehabilitation he still walks with difficulty.

Mr Johnstone, who now lives in Salisbury, said: “I went out of the sun roof and under the Transit.

“I couldn’t talk or move for two-and-a-half years. That could have been prevented. I could have still been a plumber, earning £3,000 a month. Now I’m living off compensation, I can’t work because my concentration has been affected.

“I come to tell my story to stop stupid people getting behind the wheel. Be cautious, slow down.”

Road crashes are the biggest killer of those aged between 15 and 24.