This project covers the detailed design for the first rock tunnel constructed for motorways in Thailand, running through Phunamron Mountain in Kanchanaburi Province. The facility consists of a 2-km twin tunnel with two traffic lanes in each direction.

The work included risk analysis and prevention methods, supporting function design (fire and ventilation), roadway design (pavement, sidewalk, drainage and egress), portal design, tunnel water proofing system, rock initial support (reinforcement, shotcrete, etc.), permanent lining, instrumentation, specifications, BOQ, cost estimate and tender documents.