Ensuring Safety and Security on Expressways During Heavy Rain and Typhoons in Fiscal Year 2026

May 27, 2026 NEXCO West Japan

NEXCO West Japan (Kita-ku, Osaka, Representative Director and President: Yoshiharu Shibamura) continues to take measures to strengthen road slopes for the purpose of disaster prevention and mitigation against concentrated heavy rains and typhoons that have become more severe and frequent in recent years, and actively disseminates information on the implementation status of traffic regulations, etc.

In addition, when lifting traffic regulations due to concentrated heavy rains and typhoons, we will carry out inspections and cleaning work, etc., and will properly address ensuring that customers can drive safely.

【Recent Weather Conditions】

1. Recent Weather Overview (Increase in Short-Duration Heavy Rain) 2. Worsening and Frequent Occurrence of Heavy Rain Disasters (Examples) 3. Heavy Rain Situation in August 2025

【Main Initiatives for Fiscal Year 2026】

4. Pre-preparation (Daily Preparation) 5. Efforts to Ensure Traffic During Disasters 6. Public Relations to Customers 7. Requests Regarding Traffic During Approaches of Concentrated Heavy Rain and Typhoons

1. Recent Weather Overview (Increase in Short-Duration Heavy Rain)

The average annual occurrence of hourly rainfall of 50mm or more nationwide over the past 10 years (approximately 340 times) has increased to about 1.5 times compared to the average annual occurrence (approximately 226 times) during the first 10 years of the statistical period (1976-1985).

2. Worsening and Frequent Occurrence of Heavy Rain Disasters (Examples)

3. Heavy Rain Situation in August 2025

Due to the stagnation of a front in August 2025, the Japan Meteorological Agency announced the occurrence of a linear rainband in Kyushu and western Yamaguchi, and a special heavy rain warning was issued in Kagoshima and Kumamoto prefectures, among others, observing record-breaking heavy rain.

Traffic Stop Extension Total cumulative length of traffic stops: 620.2 km (8 routes) Approximately 17% of the total managed length of 3,600 km

・ Although the length of traffic stops accounted for approximately 17% of the total length, disasters requiring a long period for restoration occurred (see Example ② below).

4. Pre-preparation (Daily Preparation)

We are taking the following preparations for concentrated heavy rains and typhoons.

❶ Preparation of materials and equipment for disaster response ❷ Cleaning, inspection, and repair of drainage facilities to prevent poor drainage ❸ Holding disaster prevention conferences in preparation for concentrated heavy rains and typhoons (initial response and reconfirmation of various criteria) ❹ Reconfirmation of communication systems with related agencies

5. Efforts to Ensure Traffic During Disasters

In case of concentrated heavy rains and typhoons, we will promptly implement traffic stops based on predetermined regulation criteria.

In the event of a disaster, we will work as a group to ensure early traffic restoration.

Example ①: Oita Expressway (Asakura IC to Hiki IC) slope collapse disaster in the Kyushu Branch Office in 2023

・ Emergency measures were implemented, and traffic was ensured by utilizing two lanes on one side of the four lanes for opposite-direction traffic while carrying out restoration work.

Example ②: Kyushu Expressway (Mizobegane Kagoshima Airport IC to Yokogawa IC) slope collapse disaster in the Kyushu Branch Office in 2025

・ Emergency measures were implemented, and traffic was opened with driving lanes regulated, while ensuring traffic by carrying out restoration work.

Efforts for Early Traffic Restoration Due to Typhoon Effects

Example ③: We will clean fallen leaves and dried leaves scattered on the road surface due to wind and strive for prompt lifting of traffic stops.

・ After a typhoon passes, a large amount of branches and fallen leaves are scattered on the road surface. While we are promptly carrying out removal and cleaning work, it may take a considerable amount of time to complete the work, so we appreciate your understanding.

6. Public Relations to Customers

In case of bad weather such as heavy rain, we will obtain detailed weather forecasts from weather companies and, considering the impact on expressways, inform you in advance of the possibility of traffic stops.

The traffic information provision app "Ai Highway" provides real-time traffic information such as traffic stops due to rain or disasters. When you go out when heavy rain is predicted, please check the latest traffic information.

● Ai Highway (NEXCO West Japan) https://ihighway.jp/ ・ You can check expressway road traffic information in maps or text information 24 hours a day. ・ Please register to receive notification emails from Ai Highway "My Route". ・ Notification emails allow you to receive information such as the start and lifting of traffic stops and accident congestion on the registered "My Route".

● Expressway Impact Information Site https://ex-ssw.com/ You can check important announcements posted on the homepages of each expressway company.

● Japan Road Traffic Information Center (JARTIC) https://www.jartic.or.jp/ You can check road traffic information including general roads.

We will actively promote through TV commercials, radio, digital signage in rest areas, etc.

In the event of a disaster, we will use press releases, HP, SNS, and other publicity media to provide information on the situation of damage, restoration work, expected lifting of traffic stops, and lifting information, etc., as appropriate.

7. Requests Regarding Traffic During Approaches of Concentrated Heavy Rain and Typhoons

We will deliver "notification" information such as the possibility of traffic stops on expressways to Ai Highway user registrants (those who receive notification emails). Furthermore, we will introduce a new "push notification" function that directly notifies the smartphone screen of those who use the Ai Highway app and set the push notification function to "ON", so please register.

When "traffic stop" is displayed on road information boards, etc., during expressway driving, please promptly exit from the nearest IC for safety.

At rest areas (SA・PA) corresponding to landslide warning areas designated by local governments, business may be suspended for safety or the entire rest area may be closed for evacuation guidance, etc. We will make efforts to provide detailed information at appropriate times and prioritize customer safety, so we appreciate your understanding and cooperation.

This year, traffic regulations may be implemented due to the effects of concentrated heavy rains and typhoons. When using expressways, please check the latest weather and road traffic information.

When lifting traffic regulations, we will promptly carry out inspections and cleaning work, etc., to ensure safe driving for customers. In the event of a disaster, we will work towards early traffic restoration. We appreciate your continued understanding and cooperation.