NETWORK Rail will carry out an in-depth review of its upgrade programme to reduce the risk of engineering work over-running in future.
Commuters experienced major problems last week after Bank Holiday engineering work in the Ipswich area was not completed in time.
Ipswich-bound services terminated at Colchester throughout the day as a result of the problems.
Greater Anglia chief executive Jamie Burles said: “Network Rail has been undertaking significant work to replace tracks and signalling in to improve reliability.
“Engineers encountered major problems overnight on Monday when integrating the newly installed equipment into the existing 30-year-old tracks and signals that are in place.
“Although eight hours of contingency had been included in their work plan, the extent of the problems encountered meant that the work was not completed on time.
“Network Rail has advised us that they intend to carry-out an in-depth review of the entire upgrade programme, which will limit the risk of work overrunning in future.”