MLIT’s Kanto Regional Development Bureau to Trial Construction Site Closures During Extreme Heat to Support Working-Style Reforms

The Kanto Regional Development Bureau of the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) will trial a system allowing construction sites to suspend operations during periods of extreme heat to support working-style reforms in the industry. The initiative aligns with the "Heatwave Countermeasure Support Package" formulated by the ministry. Under the plan, the summer season will be designated as a "semi-closed period" at the tender stage, granting contractors the discretion to decide whether to suspend operations and for how long. The measures will be applied to projects commissioned in the fourth quarter of fiscal 2025 (January to March 2026) and those funded by the supplementary budget.

The initiative follows a pilot program conducted by the bureau’s Utsunomiya Highway Office. In that pilot, consultations between project owners and contractors allowed work originally scheduled for July and August to be reallocated to other months. The operational rules are defined in the project’s special specifications. The goals of the program include preventing heatstroke and ensuring that workers can take extended summer leave to assist in the recruitment and development of the workforce.

Drawing on the results from the Utsunomiya Highway Office and other cases, MLIT established the support package in December 2025. The package encourages measures such as avoiding project tenders during peak heat periods and the use of variable working hour systems on an annual basis.

The Kanto Regional Development Bureau’s new trial designates a four-month "semi-closed period" from June to September. Contractors will be able to decide the feasibility and duration of closures without the need for prior consultation with project owners. The trial will focus on several projects, such as road maintenance, with results used to inform future system improvements.

Improving working conditions is essential for securing a sustainable workforce. As global temperatures rise, conditions at construction sites throughout Japan are becoming increasingly difficult, making heatwave countermeasures an urgent priority for the construction industry.　(2026/01/13)