Alternative rail schemes following problems caused at storm-hit Dawlish in Devon this winter offer poor value for money, a Government-commissioned report has said.
The fierce winter weather led to the line at Dawlish being wrecked and closed for weeks, meaning travel misery for train passengers in the south-west while repairs were carried out.
Transport Secretary Patrick McLoughlin asked Network Rail (NR) to identify options for a resilient rail route west of Exeter.
Presenting various options in its report, NR said that even in the best-case scenario "the financial business case and transport economic case for each new route option remain unpromising, with each one still offering poor value for money."
The report considered continuing the current maintenance regime on the existing route through Dawlish as well as strengthening the existing railway at a cost of between £398 million and £659 million over 20 years.
The alternative options were:
:: Route A - the former London & South Western Railway route from Exeter to Plymouth via Okehampton;
:: Route B - constructing a modern double track railway on the alignment of the former Teign Valley branch line from Exeter to Newton Abbot;
:: Five a lternative route Cs (C1 - C5) - five alternative direct routes would provide a new line between Exeter and Newton Abbot.
NR appraised each route in line with Department for Transport guidelines, where the project benefits and costs (BCR) ratio measures the net economic benefits per pound.
On this basis, schemes with a BCR of greater than 4.0 (£4 of benefit for every £1 spent) are deemed to be of very high value for money, while schemes with BCR of less than 1.0 are consider to offer poor value for money.
NR said the Route A scheme offered a BCR of only 0.14, with route B getting a figure of 0.29 and the C1-C5 alternatives getting between 0.08 and 0.17.
NR said that the schemes would still offer poor value for money even if certain revenue and unpriced benefits were doubled and the capital outlays halved.
Mr McLoughlin said: "We are absolutely committed to delivering world class transport infrastructure in the South West. Last month the Prime Minister announced a £130 million package of improvements but we know there is much more to do.
"This study is an important step towards achieving that goal and providing the region with a rail network that helps it thrive. And crucially, along with a package of measures already planned to boost resilience, it will ensure that there is no repeat of the disruption we saw earlier this year during the severe weather.
"I will now consider its contents before making an announcement on next steps later this year."