icon of Disaster-Prevention InitiativesDisaster-Prevention Initiatives

Earthquake Disaster Prevention

The Metropolitan Expressway is designed and constructed to withstand an earthquake on the scale of the Great Hanshin-Awaji Earthquake, according to standards set by the country. We have also taken it upon ourselves to further enhance the safety of the Metropolitan Expressway by installing devices such as the collapse prevention system with enough strength such that the girder does not fall to the ground. We are taking measures to improve the earthquake resistance of existing structures based on lessons learned from the Great Hanshin-Awaji earthquake, such as reinforcing the bridge piers and modifying the bearings.

Enhancing the safety of elevated bridges

Earthquake resistance measures for the bridge pier

Based on the lessons learned from the Great Hanshin-Awaji Earthquake from January 17, 1995, the concrete bridge piers on the Metropolitan Expressway were covered with steel plates for reinforcement in order to withstand an earthquake on a similar scale, and steel reinforcing components were added inside the steel bridge piers for further reinforcement. These earthquake resistance improvements have been completed on all bridge piers of the Metropolitan Expressway.

Image of the Earthquake resistance measures for the bridge pier

Further strengthening of collapse prevention structure and bearings
(base supporting the bridge girder)

In the event of a large-scale earthquake, the bridge may move sideways and fall from the bridge piers, so a bracket (support material) is added to the bridge piers to increase the gap for movement. Also, in order to prevent collapse, bridges are connected to each other by cables or steel plates, or connected to abutments and bridge piers. We have also taken the measure of replacing the base (bearing) that supports the bridge with a new rubber-made type that functions to restrict movement.

Image of the strengthening of collapse prevention structure and bearing measures

Measures against ground flow caused by soil liquefaction

During an earthquake, the soil of the reclaimed land near the coast may liquefy and flow. To ensure the safety of bridge piers built in spots at risk of "fluidization", piles (steel pipe sheet piles) made of durable steel pipes are hammered in side by side near the pier foundation to set up a "wall" in the ground. This wall prevents flow due to liquefaction. All of these measures were completed in 1999.

Customer safety measures during an earthquake

In preparation for an earthquake, the Metropolitan Expressway is working on safety measures such as "improving evacuation/navigation facilities" and "providing adequate disaster coping strategies for drivers to follow".

After an earthquake, the Metropolitan Expressway must also function as an emergency traffic road and an emergency transportation road. We will consider twofold and threefold safety measures aimed at keeping the Metropolitan Expressway safe, and will implement them as soon as possible.

Creating systems for information gathering and transmission during an earthquake

During an earthquake, the Metropolitan Expressway will function not only as traffic infrastructure, but also as part of the information infrastructure. We are involved in a myriad of measures to support lives, such as improving communication networks and enhancing power backups.

Metropolitan Expressway Co., Ltd. Civil Protection Operations Plan

The Metropolitan Expressway Co., Ltd. Civil Protection Operations Plan was established. The operation plan related to the protection of citizens established based on Article 36 (1) of the Act concerning the Measures for Protection of the People in Armed Attack Situations, etc. (Act No. 112 of 2004) is published here based on paragraph (5) of the same article. (We are specified as a designated public institution prescribed in Article 2 (5) of the Act on the Peace and Independence of Japan and Maintenance of the Nation and the People's Security in Armed Attack Situations etc. (Act No. 79 of 2003). (Enforcement Ordinance 3 of the same Act))

Metropolitan Expressway Co., Ltd. Disaster Prevention Operations Plan

The Metropolitan Expressway Co., Ltd. Disaster Prevention Operations Plan was established.
The Metropolitan Expressway Co., Ltd. was specified as a designated public institution prescribed in Article 2 (5) of the Basic Act on Disaster Control Measures. (Cabinet Office Notification No. 772, September 30, 2005) We publish here the disaster prevention operations plan stipulated under Article 39 (1) of the same Act, based on paragraph (2) of the same Article.

Business continuity plan (BCP) for potentially large earthquakes

To ensure the road network's function as an emergency traffic route that is capable of implementing disaster response services even if the network is damaged during a large earthquake, our company formulated a "Business continuity plan (BCP) for potentially large earthquakes, First Edition" in October 2009, but based on the issues brought to light by the Great East Japan Earthquake and tsunami and the solutions to them, the second edition was formulated at the end of October 2011. Furthermore, due to the amendment of the Basic Act on Disaster Control Measures in November 2014, the third edition was formulated based on the inclusion of regulations concerning the movement of stranded vehicles by road managers.

1. Basic items

Assumed earthquake

The potential earthquake in this BCP assumes an earthquake directly below the southern end of the city center (M 7.3) and a maximum seismic intensity of 6 upper (partially 7).

Action guidelines

The BCP supposes a situation where employees cannot contact one another in the panic immediately after the earthquake. Executives and employees should act independently if an earthquake of intensity 5 upper or greater occurs in the jurisdiction of the Metropolitan Expressway.

2. Main details

Headquarters system

In the event that a major earthquake occurs outside working hours, a system has been set such that the director in charge of disaster prevention, acting as the director-general (director), or the maintenance and transport manager will immediately rush to headquarters and run operations while remaining close to the headquarters.

Assembly system

To smoothly respond to an earthquake of intensity 5-upper if it occurs outside working hours, the company maintains an 'assembly system' in which employees living near the office (generally within a 6 km radius) will come together and form an initial assembly. In addition, the initial assembly members also instruct and guide all technicians after an intensity 5-upper earthquake.

Special traffic patrol

Including the evacuation of stalled cars and closing road entrances, the special traffic patrol is expected to implement such measures within 3 hours after an earthquake. In addition, definite evacuation methods (roads of managed PA, nearest exit, etc.) have been arranged for each toll booth

Inspection under overhead structures

The inspection priority of the route (about 88 km, about 30% of the entire route) is determined, and inspection under the overhead structure is generally done in 3 hours. In addition, we also inspect parts under overhead structures on other routes continuously and finish it as soon as possible.

Measures against tsunamis

We collect tsunami information from the Meteorological Agency and other local government bodies, understand and identify tsunami-prone areas based on that information and then determine the disaster response.

Arrangements for backup office

Backup offices have been set up assuming that the head office and other branch offices may be unusable during an earthquake.

Securing communications infrastructure

Multiple means of communication and transmission equipment have been set up such that communication can be secured between relevant organizations and within the company even during disasters.

Removing obstructions from roads

We have established procedures for removing obstructions from roads which include cooperating with relevant organizations and moving stranded vehicles.