Network Rail has offered a "full and unreserved apology" to families bereaved by level crossing accidents.
Chief executive Mark Carne apologised for "failings" in managing public safety and for "failing to deal sensitively" with affected families.
In 2012 Network Rail was been fined £356,250 and ordered to pay costs of £19,485 following a prosecution brought by the Office of Rail Regulation (ORR) for breaches of health and safety law which led to the death of Julia Canning at the Fairfield footpath and bridle way crossing at Little Bedwyn, near Marlborough.
Mother-of-three Mrs Canning was struck while walking her two dogs by the First Great Western 17:11 service travelling from Newbury to Bedwyn on May 6, 2009.
The criminal charge results from Network Rail's failure to act on substantial evidence that pedestrians using the crossing had insufficient sight of approaching trains.
Network Rail said today that since 2010 the risk at level crossings had been reduced by a quarter.
The apology came as MPs published a report heavily critical of the way the rail infrastructure company had handled tragedies in the past.
The House of Commons transport committee was particularly critical about the deaths of Olivia Bazlinton, 14, and Charlotte Thompson, 13, at Elsenham crossing, in Essex, in December 2005.
Network Rail was later fined £1m for health and safety breaches in relation to the accident.
Louise Ellman, the committee's chairwoman, said: "NR has lowered the risk of death at a level crossing by 25 per cent since 2008, but when suicides and trespass are excluded, level crossings still account for one half of all fatalities on the railway in recent years, including nine people who died in 2012-13.
"Yet, looking back, it's clear that on too many occasions Network Rail showed a callous disregard for the feelings of the families of people killed or seriously injured in accidents at level crossings.
Network Rail was fined £1m over the deaths of Charlotte Thompson and Olivia Bazlinton.
Ms Ellman said: "Victims were erroneously described as 'trespassers' or accused of 'misuse' of the railway when, in fact, they tried to use level crossings appropriately."
She said a "lack of transparency" around safety concerns at the Elsenham crossing was "particularly shocking and raises profound questions about NR's internal culture and accountability".
Speaking about the description of victims as "trespassers" by NR, she said: "I can only think it was NR not wanting to admit any liability, but it was inhumane, it was wrong and this must change."
Mr Carne said: "Today, I wish to extend a full and unreserved apology on behalf of Network Rail to all those whose life has been touched by a failing, however large or small, made by this company in managing public safety at level crossings and in failing to deal sensitively with the families affected.
"As we made clear when we pleaded guilty during the Elsenham court proceedings, it was a watershed in the way we thought about our approach to the risk at level crossings, and how we treat victims and their families.
"As a result of this transformation, level crossings in Britain are amongst the safest in Europe, but there is still much that we can, and will, do and the committee's recommendations will help us in that endeavour."
He said £130m had been spent on improving level crossing safety since 2010, including building footbridges to replace crossings, installing power-operated gates and introducing spoken warnings.
Almost 800 crossings have been closed in that time.