Thailand advances nine southern road and bridge plans worth over THB240bn

Thailand’s Transport Ministry is pushing nine road and bridge projects worth more than THB240 billion to ease southern traffic bottlenecks and support the regional economy.

Deputy Prime Minister and Transport Minister Phiphat Ratchakitprakarn outlined the broader transport strategy at the Nation Forum x Dinner Talk: Thailand’s Agenda 2027 on 20 October 2026. Phiphat described roads as feeder links within a nationwide transport network and called for faster development of southern routes, which he said had lagged behind.

Phiphat pointed to heavy reliance on the Phetkasem and Rama II road corridor as a cause of recurring congestion, particularly during major holidays.

The Transport Ministry source said financing for the nine projects would draw on government budgets, motorway toll revenues, fundraising through the Thailand Future Fund (TFFIF), public-private partnerships (PPPs) and World Bank loans.

1. M8 targets a 2033 opening for Nakhon Pathom–Pak Tho

The Department of Highways is prioritising the 61-kilometre Nakhon Pathom–Pak Tho section of the M8 motorway, with full service targeted for 2033. The first stage forms part of the planned 109-kilometre Nakhon Pathom–Pak Tho–Cha-am route.

The first-stage budget is THB54.562 billion, comprising THB14.4 billion to acquire 5,338 rai of land, about 854 hectares, and THB40.162 billion for civil works.

Civil construction on the Nakhon Pathom–Pak Tho section would be split into two packages:

• Nakhon Pathom–Talat Chinda: About 9.3–11km, THB10.509 billion, Motorway toll fund
• Talat Chinda–Pak Tho: About 50–51.8km, THB29.653 billion, Thailand Future Fund and the fiscal 2028 budget

The Department of Highways is reviewing the M8 details for submission to the Cabinet by the end of 2026. A land-expropriation decree and the start of civil construction are expected in 2028.

Full operation of the Nakhon Pathom–Pak Tho section in 2033 would include a THB6.591 billion systems, operation and maintenance package. The motorway is expected to cut journeys between the two locations from 90 minutes to 30 minutes.

2. Phetkasem parallel route planned for eight lanes

The Pak Tho–Pran Buri project would widen a route parallel to Phetkasem Road from four lanes to eight, running towards Phetchaburi through Kaeng Krachan before reaching Pran Buri.

The four central lanes would become a motorway with partially controlled access, while flyovers would carry traffic over major junctions. Funding would come from the motorway fund and the Thailand Future Fund, with the programme planned to begin from 2027.

3. M84 would connect Hat Yai with the Malaysian border

The proposed M84 motorway would run 62.4 kilometres from Phetkasem Road in Bang Klam district, Songkhla, to the second Sadao customs checkpoint on the Thai-Malaysian border. The THB40.787 billion project also includes a 7.86-kilometre spur to Hat Yai International Airport.

The M84 environmental impact assessment (EIA) has received National Environment Board approval and been acknowledged by the Cabinet. The Department of Highways is preparing to submit a revised PPP model to the Transport Ministry and the PPP committee.

 

Preparatory infrastructure for M84 includes the four-lane Highway 4369 link between Highway 4 and the second Sadao checkpoint. The 5.496-kilometre road, costing THB463 million, was completed in April 2024 with space reserved in the median for the motorway. M84 civil construction is planned for 2027–2030.

4. Hat Yai ring road targets a 2031 opening

The Department of Highways plans to seek Transport Ministry and Cabinet approval for the 66.84-kilometre Hat Yai ring road by the end of 2026. Thansettakij quoted a budget of THB5.711 billion, with tendering and construction targeted for 2028 and an opening in 2031.

The ring road’s 31.33-kilometre eastern section would run from Ban Thung Nam via Highways 407 and 43 to Highway 4 south of Hat Yai, continuing to the airport access road.

The 35.51-kilometre western section would head north from Hat Yai airport, cross Highway 4287 and connect with Highway 4 north of the city and M84, before ending at Highway 414.

5. Samui expressway targets mainland link by 2034

The Expressway Authority of Thailand (EXAT) is finalising the feasibility study for an expressway linking the mainland with Koh Samui. The 37.41-kilometre, THB74.044 billion project targets an opening in 2034.

EXAT plans to consult utility agencies before seeking Cabinet approval by 2028. Construction of the Samui link is targeted to begin in 2029.

The proposed route starts in Don Sak district, Surat Thani, passes through Khanom district in Nakhon Si Thammarat and crosses the Gulf of Thailand to Taling Ngam subdistrict on Koh Samui.

The Samui crossing would combine a cable-stayed section rising 50 metres to allow naval and cargo vessels to pass, cable-supported girder spans over coral reefs and box-girder sections.

6. Phuket expressway phase two heads towards a 2027 submission

The Mueang Mai–Ko Kaeo–Kathu section of the Phuket expressway is undergoing detailed design, with completion expected in January 2027 and submission to the Cabinet by October 2027.

The 30.62-kilometre second phase has an estimated budget of THB67.461 billion. The reported breakdown comprises THB29.547 billion for land acquisition and THB37.913 billion for construction and supervision.

The Phuket route would combine ground-level and elevated roads with a tunnel through the Kamala hills, joining phase one near Highway 4029. A spur at Ma Nik 2 would provide access towards Phuket town.

The Phuket project also includes a 37-rai service area and a 13-rai rest stop, with private-sector participation planned for both facilities.

7. Songkhla Lake bridge scheduled for construction from November

The Department of Rural Roads has signed a construction contract for the Songkhla Lake bridge and is scheduled to issue the notice to proceed on 14 November 2026. Construction is expected to take three years, with an opening targeted for 2029.

The 6.6-kilometre project would connect Ko Yai subdistrict in Krasae Sin district, Songkhla, with Chong Thanon subdistrict in Khao Chaison district, Phatthalung. Thansettakij quoted a budget of THB4.604 billion and reported that the EIA and Cabinet approval of the loan agreement were complete.

The reported Songkhla financing plan comprises 70% World Bank borrowing, approximately THB3.29 billion or US$101.86 million, and 30% government funding, approximately THB1.41 billion.

The Songkhla bridge would use cable-supported and concrete box-girder spans, with railings featuring Manora performing-arts motifs. The crossing is expected to shorten an 80-kilometre detour to seven kilometres and reduce journeys from two hours to 15 minutes.

8. Koh Lanta bridge would replace the vehicle ferry

The planned Koh Lanta bridge in Krabi would replace the existing vehicle ferry, with completion scheduled for 2029. The Department of Rural Roads plans to issue the notice to proceed on 14 November 2026.

The Department of Rural Roads has signed the Koh Lanta construction contract with a Malaysian company. The project’s EIA and Cabinet approval of the loan agreement are complete.

The THB1.781 billion project would connect Ko Klang and Ko Lanta Noi subdistricts. The route totals 2,240 metres, comprising a 1,825-metre bridge and 415 metres of connecting roads.

The reported Koh Lanta financing plan allocates 70%, approximately THB1.26 billion, to World Bank borrowing and 30%, approximately THB540 million, to the government budget.

The Koh Lanta bridge is expected to cut crossing times from one to two hours to about two minutes. The connection would also support emergency patient transfers and evacuations during disasters.

9. Southern coastal-road programme spans five phases

The southern coastal-road programme covers routes managed by several agencies, with the Department of Rural Roads’ work divided into five phases. The first phase is complete, while other sections are being studied, prepared for construction or built.

Separately, the Department of Rural Roads plans to spend THB21 million in fiscal 2027 surveying and designing a roughly 30-kilometre Thailand Riviera route between Sichon and Tha Sala in Nakhon Si Thammarat.

Source: Thansettakij