Infrastructure failures affecting Govia Thameslink services occurred every 1.5 hours in 2016, a National Audit Office (NAO) investigation into the franchise found.
The public spending watchdog said that 37% of all cancellations and delays of more than 30 minutes on the Thameslink, Southern and Great Northern rail franchise were caused by Network Rail, mainly due to failures in the infrastructure and its management of the network between July 2015 and March last year.
Between September 2014 and September last year passengers on the franchise experienced the worst service performance in the country, a report published this morning said.
It will cost the rail operator £900M to resolve the issues it identified with infrastructure, however it had to prioritise £300M of works to reduce delays in central London and support the new Thameslink programme timetable. Works are expected to finish by April 2019.
The Department for Transport (DfT) has given Network Rail a £250M grant, and the remaining £50M will be “reprioritised” from the existing maintenance budget. The additional £600M of works are being considered for the next railway spending period in April next year.
NAO head Amyas Morse said: “Over the last three years long-suffering passengers on the Thameslink franchise have experienced the worst performance on the rail network. Some of the problems could have been avoided if the Department had taken more care to consider passengers in its design of the franchise.”
The DfT and Network Rail did not have a good understanding of the underlying condition of the network when the Department set the requirements of the franchise, the report said.
A Network Rail spokesperson said: “The reliability of the railway in the south east is at historically high levels, however growing passenger numbers and congestion has meant that even small incidents can cause significantly more delay than in other less crowded parts of the network.
“The completion of the Thameslink Programme alongside a £300m programme to boost the reliability of tracks and signalling will deliver big benefits for passengers, and we continue to work closely with train operators to deliver a better, more reliable railway.”
Govia Thameslink Railway chief executive Charles Horton said: “Thameslink, Southern and Great Northern is the UK’s largest franchise – carrying almost a million passengers a day – and the report identifies numerous root causes for the challenges it has faced since its formation in 2014. These difficulties have sometimes been greater than expected and we regret the disruption caused to our passengers.”
A DfT spokeswoman said: “Clearly the disruption passengers have experienced is unacceptable but the NAO recognises that service has improved over the last 12 months. The Government has taken a number of steps to ensure this improvement, including the provision of an additional £300 million to improve reliability on the Brighton Mainline. We expect service improvements to continue as the Thameslink programme is completed.”