The parents of an autistic woman are publishing a book featuring her writing to help "prevent the mistakes" of her death from being repeated.
Colette McCulloch, 35, was killed in July 2016 when she was hit by a lorry on the A1 while a voluntary patient at a care home in Bedfordshire.
In 2019 a coroner said her death was an "avoidable tragedy" and found the home should have kept her safe.
Her mother Amanda said the book was for young people "who feel different".
Her husband Andy said his daughter was a "very talented, very interesting, extraordinary child, but clearly with a number of problems".
"She suffered from dyslexia, anorexia, obsessive compulsive disorder, panic attacks," said Mr McCulloch.
"She went on to university and did a degree in English which was what she always wanted to do.
"But she could never relate to people, she could never make friends, she could never establish relationships and it wasn't until she was 33 that she was diagnosed with high-functioning autistic spectrum disorder.
"Then from there on within two years of that diagnosis she was dead.
"That really happened because the treatment was not adequate, they didn't know what they were doing or they didn't really deliver what they said they were going to deliver."
Coroner's 'considerable distress'
Following an inquest nearly three years after her death, assistant coroner Martin Oldham said in his narrative conclusion that Ms McCulloch "was failed by a lack of a mental health assessment and by an inadequate regime of care".
He noted that Ms McCulloch was vulnerable and incapable of keeping herself safe.
When anxious she turned to alcohol and this was a factor on the night she died but "no-one will ever know how she came to be on the A1", Mr Oldham added.
He said Ms McCulloch "died as a result of failures for which no person directly is at fault nor any single or combination of organisations".
"This causes me considerable distress," he added.
'Sonnets to break your heart'
Mr McCulloch said that after the inquest the family wanted to raise awareness about autism and came up with an idea for the book, called "Why Can't You Hear Me?", because of his daughter's love for writing.
"Like all bereaved families, we're not looking for anything other than to stop this ever happening again if that's possible," he said.
"If we can prevent the mistakes that happened to Colette happening to other people then we will have got somewhere."
The book includes extracts from her diaries, poetry and letters, which were collated by her mother Amanda.
Mr McCulloch said his daughter "understood the difficulties that she had and the difficulties the world put in her way that she couldn't achieve what she wanted to achieve because people didn't understand her".
"She expresses it better than I ever could - it was important to get that out there so people understand that autism isn't something you cure, you learn to manage it but they have insights that non-autistic people don't, they're incredibly useful insights."
Mrs McCulloch said the family were "always hoping that one of these medics is going to be able to tell you why she isn't able to deal with the world".
"This girl can write sonnets to break your heart but can have a meltdown in Sainsbury's over whether to choose cauliflower or broccoli."
She added: "It's not just for Colette, our book, it's for all the other young people who feel different.
"What she writes about is [being] alone, different, shut out, not understood."
The BBC has contacted Ms McCulloch's care home for comment.