LOS ANGELES (AFP) - A US family has published the last, cut-off text message written by their 22-year-old son who crashed his car and died while using his cellphone, in the hope of preventing similar tragedies.

Mr Alexander Heit, a 22-year-old student, drifted across the road while exchanging texts with a friend, realised suddenly and over-corrected with the steering wheel, sending his car rolling off the road.

He was pronounced dead at North Colorado Medical Center on April 3 after the late afternoon crash - and his family have agreed with police to issue a photograph of his last text exchange.

The text shows two messages from a friend, who says: "Hey man I had to run out for like an hour," to which Mr Heit was replying: "Sounds good my man, seeya soon, ill tw .." before abruptly stopping.

"Heit had been traveling eastbound .. Witnesses stated he seemed to have his head down, and began drifting into the oncoming lane of traffic. A westbound vehicle slowed and moved over just before Mr Heit looked up.

"As he did, he jerked the steering wheel hard, over-correcting, resulting in his leaving the south side of the roadway, rolling and flipping the vehicle," said a statement by police in Greeley, north of Denver.

His mother Sharon Heit said: "I can't bear the thought of anyone else having to go through something like this.

"Please, vow to never, NEVER text and drive. In a split second you could ruin your future, injure or kill others, and tear a hole in the heart of everyone who loves you," she added, cited by the police statement.

Police chief Jerry Garner added: "Unfortunately, when we think to ourselves, 'I'll just do it this one time,' we are fooling ourselves.

"This 'one time' may be the only time. The Heits are sharing their tragedy and loss, in hope that through Alex's story, others may realise and recognise just how dangerous texting and driving is."