The government's proposed high-speed train network is unlikely to win over passengers from budget airlines if operating costs are the main factor.
Executives of major discount carriers Thai AirAsia (TAA) and Nok Air say their operating costs are definitely lower than those of high-speed trains, which, according to the Office of Transport and Traffic Policy and Planning, are estimated to be 2.50 baht per kilometre.
TAA claims its cost is 5 US cents (1.48 baht) per km, while Nok Air says its is 2.30 baht.
"Unless the government opts to subsidise fares, the rail network cannot beat LCCs (low-cost carriers) in terms of operating costs and fares," said TAA chief executive Tassapon Bijleveld.
Vitai Ratanakorn, chief financial officer of Nok Air, said the rail network, due to its prohibitive investment outlay, cannot compete with LCCs on fares.
Speaking to the Bangkok Post separately, the executives agreed that the rail network and LCCs do not necessarily compete head on and tend to complement each other as they have different merits and purposes.
"The high-speed rail system serves sightseeing purposes and, to a certain extent, moving cargo, while LCCs have a speed advantage," said Mr Tassapon, pointing out that a TTA flight from Bangkok to Chiang Mai takes one hour compared with more than three hours on a high-speed train.
Mr Vitai believes air and rail passengers form different segments.
"Ours are those wanting to travel directly from one point to another, overflying cities where the train may stop en route," he said.
"I think the high-speed railway and LCC passengers have different needs. It's not necessary that they will steal passengers from each other."
Mr Tassapon cited the example of Europe, where high-speed trains and LCCs are well developed and co-exist without one crushing the other.
"Have you seen the train clip the wings of EasyJet? No, EasyJet is still alive and kicking," he said.
"I think all things in life come down to crucial words like price, demand and supply, and these are relevant to the rail network versus LCC issue."
The Thailand Development Research Institute (TDRI) says the four planned rail lines linking Bangkok with Chiang Mai, Nong Khai, Rayong and Padang Besar will cost more than half of the 2-trillion-baht infrastructure budget.
TDRI researcher Sumet Ongkittikul has questioned the economic viability of the projects, saying such an undertaking will never break even.
High-speed train systems elsewhere in the world need at least three million passengers in the first year of operation if they are to have any hope of breaking even, but the Thai network will need at least three times that number due to the excessive investment cost, he said.
But Transport Minister Chadchat Sittipunt has insisted the broad economic returns will make the rail projects worthwhile.
The 745-km Bangkok-Chiang Mai route is due to be the first operational high-speed line, with the first section from Bangkok to Phitsanulok expected to launch by 2018-19, followed by the second section to Chiang Mai in 2021.
The first phase of the Northeast line will stretch to Nakhon Ratchasima, while the southern route will first extend to Hua Hin.