Phuket Expressway and Kathu–Patong Tunnel Opening Delayed Until 2031

Construction of the Kathu–Patong tunnel is now scheduled to begin no earlier than October 2027, while the planned opening of the Phuket Expressway has been pushed back to October 2031.

The latest timetable was confirmed in September by Thailand’s Expressway Authority (EXAT) and the government. The project has already gone through several revisions, with its implementation schedule repeatedly changing over recent years.

According to the current plan, Phase 1 of the Phuket Expressway, linking Kathu and Patong, is expected to be submitted to the Cabinet for approval in December 2026. Land acquisition is targeted for completion by January 2027, while a contractor is expected to be selected through a bidding process around April.

Construction is then scheduled to begin in October 2027.

The construction period is expected to last four years, with completion targeted for September 2031 and the road opening to traffic in October 2031.

Updated Phuket Expressway timeline

Phase 1: Kathu–Patong Expressway

• Length: 3.98 kilometres

• Cabinet submission: December 2026

• Land acquisition target: January 2027

• Contractor selection: April 2027

• Construction start: October 2027

• Opening: October 2031

The 3.98-kilometre route will include an elevated section and a 1.85-kilometre tunnel through the mountain between Kathu and Patong. The tunnel is the central part of the project and is expected to provide a new alternative to the existing road between the two areas.

The estimated cost of Phase 1 is currently 16.757 billion baht. Of this amount, 5.792 billion baht is allocated for land acquisition, while 10.965 billion baht is earmarked for construction and supervision.

Phase 2: Muang Mai–Koh Kaew–Kathu Expressway

• Length: 30.62 kilometres

• Cabinet submission: September 2027

• Construction start: October 2028

• Opening: October 2031

The second phase is designed to connect the airport area with Bypass Road and Wichitsongram Road in Kathu. Its estimated investment is 46.752 billion baht, including 22.012 billion baht for land acquisition and 24.740 billion baht for construction and supervision.

Both phases are currently targeted for opening in October 2031.

Tunnel design and financing

The Kathu–Patong project has also undergone changes to its technical design. EXAT has reduced the planned tunnel width from 17 metres to 14 metres, with the revised design being reviewed by the relevant agencies. The project still requires Cabinet approval before the next stages can proceed.

EXAT is also preparing to raise around 20 billion baht through an infrastructure fund to support Phase 1. The proposed financing mechanism would allow funds to be raised in stages according to project requirements, while the infrastructure itself would remain state-owned and investors would receive returns linked to the associated revenue streams.

According to the current financing plan, around 14 billion baht of the infrastructure-fund proceeds could be allocated to the Kathu–Patong tunnel project, with the remaining amount potentially supporting other road projects in southern Thailand.

Five-minute journey between Kathu and Patong

Once completed, the new route is expected to reduce travel time between Kathu and Patong from around 30 minutes to approximately five minutes.

Traffic on Phase 1 is projected at around 50,000–60,000 vehicles per day, including motorcycles. The project is intended to provide an alternative connection between the two areas and reduce pressure on existing roads.

The latest timetable means the Phuket Expressway will not open by the earlier dates previously discussed for the project. For now, October 2031 remains the government's target for opening both phases, subject to the required approvals, land acquisition, procurement and construction.