On September 3, 2026, Japan's Ministry of Land, Infrastructure, Transport and Tourism (MLIT) held the award ceremony for the 9th Japan Construction International Award. The National Road No.5 Improvement Project Middle Section Contract Package 2 (Pursat-Pray Svay), constructed by Obayashi Corporation in Cambodia, received the award in the Construction and Development Project Category. This marks the seventh time Obayashi has received a Japan Construction International Award.

National Road No.5 is a major arterial highway in Cambodia connecting the capital, Phnom Penh, with the Thai border and forming part of Asian Highway Route 1. The deterioration and insufficient width of the existing road presented challenges, creating a need to improve transport capacity and safety.

The project involved rehabilitating the existing road and bridges and widening the road from two lanes to four. Of the total 366 km covered by the National Road No.5 Improvement Project, Obayashi was responsible for a 47 km section extending from Pursat Province to Battambang Province.

The widening increased the road's capacity to accommodate traffic, including heavy vehicles, and improved traffic flow. As a result, travel time between Pursat and Pray Svay was reduced from approximately three hours before construction to about one hour. In urban areas, drainage facilities and sidewalks were developed in an integrated manner, improving sanitary conditions along the road and pedestrian safety.

Prior to construction, measures were taken to mitigate landmine risks in cooperation with the Cambodian Mine Action Centre. In addition, continuous monitoring using drones and web cameras, ICT-based construction management, and detailed scheduling enabled the project to ensure quality and safety while shortening the construction period by two months.

The project employed more than 1,400 local personnel, while Japanese engineers provided direct on-site guidance in quality and safety management. The project also promoted employment opportunities and skills development for women, contributing to women's social advancement and sustainable employment. Through rigorous safety management, the project achieved 7.7 million accident-free work hours, another of its key achievements.

The project was highly evaluated for initiatives including extending the service life of the road, providing employment and human resource development opportunities regardless of gender, implementing rigorous safety management, using digital technologies to optimize project progress monitoring and the deployment of equipment and materials, and undertaking voluntary road cleaning during the warranty period. Together, these initiatives contributed to high-quality infrastructure development in the local community and to the advancement of construction technology in Cambodia.

Obayashi Corporation will continue to contribute to creating safe and secure societies by applying the construction technologies and expertise it has developed in Japan to infrastructure development overseas.