A 24-year-old man described as a "lovable rogue" died after being hit by a train in the early hours of Saturday.
Levi Jay Nash from Cardiff died on December 8 in Cwmbran after being struck by a train.
The family believe Levi, of Gabalfa, intended to board a train to Cardiff but realised he was heading in the wrong direction.
They believe he left the train and crossed the tracks to reach the other side and was hit.
Family and friends have described Levi as "selfless" and "generous, respectable and lovable".
Levi's grandfather Colin Nash, said: "He was a a character, he was a lovable rogue.
"We have always got on together and he was active in the community.
"I was his role model, he always had respect for me."
He described Levi as "generous, respectable and lovable".
Levi's mum Tania Nash, 44, said her son left the family house on Friday night in "good humour" to head to Newport.
Levi was in Newport to support his close friend Marvin Heron who was performing in the city.
His family said he was last seen on CCTV in a nightclub at around 1.30am and was hit at around 5am.
On Saturday morning mum Tania heard a car arrive outside the house and believed it was Levi returning home.
She said: "I heard a car door and I said to my little boy to see who it was.
"He said it was the police. I thought he might have got into trouble."
She added: "We had our ups and downs, [but] he turned his life around."
Following news of Levi's sudden death the family said the community have rallied around and hundreds attended a number of vigils held over the weekend.
More than £1,000 has been donated to the family to help pay for funeral costs and a number of events are planned in Levi's memory.
Levi's auntie Beckie Nash, 28, is due to give birth on December 20 and plans to include Levi's name in her son's name.
Beckie said: "We just feel like we're in a bubble. People are just going on with their lives and laughing and they don't know the grief we are going through.
"People are more angry because we don't have anyone to blame."
British Transport Police said the death is not currently being treated as suspicious.