Tyler Byrne was fatally struck by the train at Surbiton on February 9, 2021.
He was part of a four-person group of track workers, undertaking inspections at the location while trains were running in both directions.
The train, which was travelling from London Waterloo to Salisbury, was running at around 76 mph when the incident occurred.
Last week, Network Rail, which owns the track, was fined £3.41 million and ordered to pay costs of £43,096.39 after pleading guilty to a health and safety offence.
This followed an investigation and prosecution by industry regulator the Office of Rail and Road (ORR).
The probe found that there was no protection and an inadequate warning system in place at the time of the accident.
This, the regulator said, exposed all members of the working party to the risk of being struck by a train in the course of their work.
The ORR had previously served Network Rail two improvement notices in July 2019, requiring it to implement preventive and protective measures to safeguard workers on or near the line.
The regulator said that while Network Rail had made some improvements to track worker safety at the time of Mr Byrne’s accident, its implementation across the organisation “lacked urgency and pace”.
However, in recent years there has been a reduction in red-zone working, when lines remain live during track work, while new technologies have been introduced to reduce the risk of harm, the ORR added.
Richard Hines, the regulator’s HM Chief Inspector of Railways, said: “Our deepest sympathies are with the family, friends and colleagues of Tyler Byrne.
“At just 30 years old, Tyler had a bright future ahead of him – I am sure that he would have gone on to achieve all his hopes and dreams with those who he loved the most.
“He, however, was sadly denied that opportunity. I am so sorry for the loss of his life.
“Our industry’s track workers play a crucial role in delivering a safe railway for passengers and users of the system, often working in challenging and difficult conditions.
“It’s essential that they are also protected from harm.”
Ellie Burrows, Managing Director, Southern Region for Network Rail, said: “We accept today’s judgment and are deeply sorry for what happened.
“Any life lost on the railway is one too many and since this tragic event we’ve continued to take significant steps to improve safety.
“Today’s judgment is a sobering reminder of why safety must remain at the very forefront of our minds.
“Tyler’s death will never be forgotten, and we will continue to strive to ensure something like this never happens again.”
