Some 32% of Japan's 41,395 mostly aging bridges supervised by local municipalities are in need of safety improvements, but these essential measures are still pending, according to government data.
Since these measures have not been implemented as of March due to shortages of skilled labor and funding, the Ministry of Land, Infrastructure, Transport and Tourism plans to provide financial help and other support to encourage the municipalities to address the problem swiftly.
The bridges were determined by authorities between fiscal 2014 and fiscal 2018 as requiring repair, reinforcement or demolition, among various government measures to ensure safety, the ministry said.
According to the data, certain measures have been taken for 52% of the deteriorating or faulty bridges, while implementation is still ongoing for 16% of such structures.
The ministry said that provisional steps have been taken, such as closing traffic around bridges that are considered highly dangerous.
The data showed that such bridges maintained by the municipalities are the most in need of repair and maintenance, compared with those administered by the state at a ratio of 1%.
The corresponding figure for bridges run by expressway operators was 5%, while those controlled by prefectures and ordinance-designated major cities such as Osaka and Nagoya accounted for 11%.
Mandatory safety checks on bridges and tunnels nationwide are now conducted every five years in the wake of the 2012 ceiling collapse of the Sasago Tunnel on the Chuo Expressway that killed nine people in Yamanashi Prefecture.
During the incident, three vehicles were trapped after a 138-meter part of the concrete ceiling collapsed. An investigative panel under the transport ministry later concluded that the expressway operator had not conducted proper inspection and maintenance.
For mandatory safety inspections, bridges and tunnels are examined on a four-tier scale, with the worst grade requiring urgent safety measures due to potential hazards.