Darling said: "Its sole focus is to establish the causes of accidents and to learn lessons."
The announcement came weeks after the industry was rocked by a major accident at Potters Bar in which seven people died.
The accident led to accusations of poor maintenance by rail contractor Jarvis.
Darling claimed that rail safety problems centred on management. He said: "There always have been subcontractors in the industry. That's not the problem. The problem is that, in too many cases, not enough attention is being paid to making sure subcontractors do what they are supposed to do."
Darling made his speech days after troubled infrastructure firm Railtrack, which went into administration last October, was sold to the government-backed, not-for-profit firm Network Rail for £500m.