Rail regulators have set Network Rail (NR) a target of reducing disruption to passengers from engineering work by more than a third over the next five years.
The Office of Rail Regulation (ORR) said disruption must be cut by 17% within three years and by 37% within five years.
It also told NR that it had to implement a programme of improvements to the way it manages engineering work to reduce unplanned disruption when work overruns.