Stock investors have yet to buy into Thailand’s plan for a 2 trillion baht ($63 billion) expansion of railways, roads, airports and ports.

The SET Construction Services Index of builders that should benefit from an infrastructure drive has tumbled 16 percent in the past three months. That’s a record drop in the 19-member gauge for rolling quarterly periods, despite the military government’s pursuit of a transport network overhaul.

“There are a lot of news reports about projects, but progress remains slow,” said Polpat Karnasuta, chief executive officer of Nawarat Patanakarn Pcl, a construction firm based near Bangkok. “We’re unsure about hitting our annual revenue target because the pace of government project implementation was sluggish in the first quarter.”

Adding infrastructure to support investment is one of the Thai administration’s flagship policies to bolster an economy where the rate of growth is slower than in Indonesia, Vietnam and the Philippines. The key question is how much of the vision will be implemented and whether challenges such as funding, land acquisition and environmental approvals will cause delays.

Thailand’s transport action plan includes projects such as a $5.6 billion high-speed train line to be built with Chinese help, a $6.3 billion rail link to connect three airports and an expansion of mass transit in Bangkok.

Some progress is visible in the capital, where new mass transit routes are being built by such companies as Ch. Karnchang Pcl, Sino-Thai Engineering & Construction Pcl, Italian-Thai Development Pcl and Unique Engineering & Construction Pcl.

Port Investment

On Tuesday, the Thai unit of billionaire Li Ka-shing’s Hutchison Port Holdings Ltd. said it’s constructing a $600 million terminal at Laem Chabang port, with an initial phase due to start operations this year. The port is in the Eastern Economic Corridor, an industrialized zone the government has earmarked for a fresh phase of development.

Other projects, such as the high-speed rail lines, are at early stages.

“Bidding for many projects has been delayed and the use of new budget disbursement rules slowed down the process,” said Jitra Amornthum, the head of research at Finansia Syrus Securities Pcl in Bangkok. Jitra expects the pace of implementation to quicken in 2018.

‘Loopholes’

Big projects worth 50 billion to 100 billion baht will feed into the Thai economy this year, boosting gross domestic product growth as much as half a percentage point, according to the University of the Thai Chamber of Commerce.

Implementation has been slow because officials want to close loopholes for corruption, but will improve, according to Thanavath Phonvichai, an economist at the university.

Government spokesmen didn’t immediately reply to requests for comment on infrastructure progress.

The SET Construction Services Index has declined 21 percent since the coup in Thailand in May 2014, even as the generals prioritized infrastructure. The SET Index climbed 25 percent in the same period.

“Large government projects have been the only hope for Thai construction companies,” said Raenoo Bhandasukdi, an analyst at KT Zmico Securities Co. in Bangkok. “New bids have taken longer than expected, hurting sentiment toward those stocks.”