The chief executive of Network Rail, Mark Carne, has made an "unreserved apology to those who have been let down" by the authority's failings in managing the risks of level crossings.
Speaking on Daybreak, Mr Carne also apologised for the behaviour of Network Rail in dealing with the bereaved.
In response, Chris Bazlinton - father of Olivia Bazlinton, who died at a level crossing in 2005 - said he was "encouraged" by the comments and would be holding Network Rail to account.
Mr Bazlinton added: "I think the future is bright. I think this report will lead to much safer railways."
Network Rail need to approach the safety risks caused by level crossings with "much more urgency", the head of the transport select committee has said.
Louise Ellman told Daybreak some level crossings could be closed, while "others can be changed" if Network Rail prioritised the necessary changes.
A House of Commons Transport Committee report on level crossing safety has been especially critical of Network Rail's handling of Elsenham level crossing tragedy in Essex in December 2005 in which Olivia Bazlinton, 14, and Charlotte Thompson, 13, were killed.
Chief executive Mark Carne followed severe criticism in a report by MPs of Network Rail's treatment of families affected by level crossing tragedies by issuing a "full and unreserved" apology.
"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.
"Nothing we can say or do will lessen the pain felt by the families of those killed or injured at a level crossing. Today NR is a very different company to the one which existed at the time of these tragic accidents." Mr Carne said.
Families bereaved by level crossing accidents will receive a "full and unreserved apology" from the boss of Network Rail today.
The move from NR chief executive Mark Carne followed severe criticism in a report by MPs of NR's treatment of families affected by level crossing tragedies.
Hundreds of level crossings throughout the UK could be exceeding official death-risk limits, says an MPs report.
"Calculating which level crossings are the most risky is complex but we estimate that there may be many hundreds of crossings which exceed Health and Safety Executive guidance on the acceptable level of fatality risk to the public." the report said.
A House of Commons Transport Committee report on level crossing safety has said that Network Rail (NR) admitted its behaviour towards bereaved families "has been appalling".
On "too many occasions" Network Rail (NR) had shown a "callous disregard" for families bereaved by accidents at crossings, said the chairman of the committee producing the report.
Rail regulators should set a target of zero fatalities at level crossings from 2020, added the report from the House of Commons Transport Committee.