Thailand’s DOH faces bribery scrutiny over procurement gaps

The Department of Highways (DOH), under the Ministry of Transport, is regarded as one of the state agencies with one of the country’s largest investment budgets.

In fiscal 2026, it was allocated as much as THB131.932 billion to carry out its core missions of planning, constructing, maintaining, and rehabilitating the national highway network, as well as inter-city motorways.

However, these missions are directly tied to the exercise of state power in managing national resources, both through state budgets drawn from taxpayers’ money and through authority to inspect and accept construction work of enormous value.

It also has important duties in supervising safety-related operations, such as weigh stations and traffic management.

Moreover, missions involving large budgets and many contractors have put the agency in focus in a report by the Joint Standing Committee on Commerce, Industry and Banking (JSCCIB), which stated that the Department of Highways had a rate of inducement or bribe offers of up to 82.0% of the number of contacts.

The figure came from a private-sector survey on transparency in government operations and placed the agency among the leading state agencies in the high-risk group.

Examining approval mechanisms and tax loopholes

For the Department of Highways, a state agency under the Ministry of Transport, its authority covers consideration of approvals and permits in several areas that have a broad impact on businesses and the public, especially permission for individuals or agencies to build access roads to and from highways for land plots, commercial buildings, or business premises.

It also has authority to carry out inspections and enforcement through truck weigh stations, which has become the root of the so-called “highway bribes” or “sticker bribes” problem, with off-system cash circulation of as much as THB20 billion a year.

In tax terms, the loss is not only state money leaking out as kickbacks in procurement, at as much as 20-30% of project value, but also affects the private sector’s accounting system because bribes paid in cash cannot be legally recorded as expenses under the Revenue Code.

DSI says operators buy fake tax invoices to book ‘input tax’

A news report from the Department of Special Investigation (DSI) said business operators often buy fake tax invoices to record as “input tax” before using them as credits against output tax and creating false costs in their accounts, giving them expenses to deduct from profits and enabling them to withdraw cash to pay bribes.

The practice was described as damaging the economy in the long term.

This case study can be seen clearly in a DSI case in which it arrested members of a network using fake tax invoices that caused more than THB450 million in damage to the state.

Transport ministry talks to clear bribery issue

A source at the Ministry of Transport said that, after the Department of Highways was named among state agencies accused of taking bribes, the ministry recently issued a written order to examine the facts.

The Transport Minister assigned the ministry’s permanent secretary to appoint a fact-finding committee.

The Department of Highways will proceed in line with regulations and wait for an appointment from the permanent secretary to explain details and affirm that it was not involved as alleged.

On measures to prevent and close legal loopholes so as not to be involved in bribery, the Ministry of Transport source said the Department of Highways had called a meeting to instruct relevant units to review work procedures, especially processes requiring discretion.

It also ordered a review of all work processes to identify risk points that could lead to corruption.

Conclusions on the approach under the ministry’s instructions are expected soon.

“Regarding private-sector concerns about transparency in public tendering systems that could provide a channel for bribery, there is confidence that the electronic procurement system (e-bidding) currently in use is transparent, as it is a standard process used nationwide under requirements set by the Comptroller General’s Department. It is considered stringent and auditable,” the Ministry of Transport source said.

A ‘legal crisis’ at odds with transparency

Thailand’s legal and regulatory structure has been likened to a “Hydra”, with many heads and such complexity that it is difficult to control.

Accumulated and outdated regulations not only create compliance costs but are also a major obstacle that makes official procedures cumbersome.

The survey found that procedural complexity was the main reason, at 29.1%, that businesses agreed to pay bribes.

This came even as the Department of Highways has tried to improve transparency by using technology such as the barrier-free toll collection system (M-Flow) to reduce interaction between officials and the public, as well as the Comptroller General’s Department’s electronic government procurement system (e-GP), which aims to reduce face-to-face contact between state agencies and contractors and to end the practice of identifying buyers of tender documents.

At the same time, changes to key laws, such as the Public Procurement and Supplies Administration Act 2017, still face implementation problems that raise questions about transparency, especially conditions for upgrading contractors that continue to reserve most work for only a few special-class contractors.

This has been criticised as allowing passive beneficiaries to wait for kickbacks from bid rigging.

A news report from the Office of the National Anti-Corruption Commission (NACC) found that “trading in information” about bidders in the e-GP system still occurred, enabling price collusion in advance.

Furthermore, the e-GP system still lacks efficiency in tracking operations after contracts have been signed, creating a vacuum in which officials can seek benefits in exchange for facilitating work acceptance inspections or by delaying the disbursement of payments tied to work instalments.

A windfall for 79 ‘special-class contractors’

The hottest issue is the loophole in the Public Procurement and Supplies Administration Act 2017, which has been used to block fair competition, especially for upgrading contractors.

Information from the opposition’s debate on the fiscal 2026 budget in the House of Representatives stated that only 79 special-class contractors monopolised road construction projects worth more than THB500 million, with claims that tactics were used to set inflated reference prices and lock specifications in the terms of reference (TOR) to block contractors in other classes from competing.

Statistical data clearly showed that, in projects won by special-class contractors, the state saved only 0.40% of the reference price, while projects opened to Class 1 contractors to compete freely saved as much as 17.10%.

The missing difference has been criticised as hidden “kickbacks”, with estimated damage ranging from THB300 million to THB8 billion a year.

Permits open the way to payment demands

The procedure for seeking approvals or permits from the Department of Highways was described as often lacking clear standards and taking a long time.

For example, in applications for permission to build access roads to and from land plots, officials have discretion to consider whether the application meets the criteria.

Various methods are often used, such as not registering submissions within the required timeframe or gradually requesting small revisions one by one, to keep extending the process.

Such behaviour indirectly pressures business operators to pay “facilitation fees” or “grease money” to speed up the process.

However, according to the JSCCIB survey, more than 52.3% of businesses believe these extra payments really help work move faster.

Moreover, in procurement, the process of setting the terms of reference (TOR) and reference prices is often interfered with to lock specifications or set inflated reference prices, benefiting networks of associates of those in power.

The core of the bribery problem in the Department of Highways is that it gives officials too much room to exercise personal discretion, which accounts for 25.0% of the solicitation of benefits.

This ranges from discretion in choosing procurement by a specific method for projects worth no more than THB500,000, often through split purchases or split contracts to avoid fair price competition, to the decision-making power of weigh-station officials who can choose whether to let overweight trucks pass or take enforcement action against them.

In addition, the lack of clear legal definitions of interested parties or the scope of official authority allows officials to interpret the law in ways that benefit themselves or their associates.

This not only undermines the competitiveness of honest businesses but also means taxpayers’ money is spent on projects that lack quality and do not provide value for investment.