The families of people killed in the Hatfield rail crash are preparing to go to court to seek compensation.
Four people died in the crash
Railtrack accepted liability very soon after the incident in October 2000, but families' claims have not yet been settled.
Four people died in the crash in Hertfordshire when a broken rail caused a GNER East Coast high-speed train to derail about half-a-mile south of Hatfield station.
Another 34 people were injured in the crash when carriages overturned.
John Pickering, head of personal injury at the law firm Irwin Mitchell which is dealing with the claims, said there was still the chance of an amicable outcome.
"Sadly the other side has not come forward with offers of settlement despite our requests," he told BBC Radio 4's Today programme.
"I am having to commence court proceedings so as to ensure the case is brought to a conclusion.
"Hopefully we will still achieve settlement, but if not we will be prepared to go to court."
The Hatfield incident was the third serious rail disaster in three years after the Southall and Paddington crashes.
Mr Pickering said he did not understand why the settlements were taking so long.
He said the issue was the amount of compensation to be paid, not whether or not it should be paid.
A statement by Railtrack said: "We will continue to work with our insurers to settle outstanding claims as quickly as humanely possible."
The firm also says it has made interim payments to those affected by the tragedy.
The four people killed in the Hatfield crash were airline pilot Robert Alcorn, 37, of New Zealand; advertising
executive Peter Monkhouse, 50, of Leeds; solicitor Leslie Gray, 43, of
Nottingham, and Stephen Arthur, 46, of West Sussex, who worked in the aircraft