It’s common knowledge that Japan faces major challenges because of its rapidly aging population, but did you know the country also has a looming problem with aging bridges? The importance of keeping up with bridge maintenance was brought into the spotlight in Japan by the 2007 collapse of a major bridge in the United States, the Interstate 35-W bridge in Minneapolis. People began to realize it was just a matter of time before a similar tragedy occurred here, unless something was done. In Japanese, the issue is referred to as hashi no rekka (橋の劣化、the deterioration of bridges）.
Bridges start to really show their age after around fifty years of wear and tear, but their usefulness can be extended if they get timely reinforcement. The problem in Japan is that a very large number of bridges are all coming due for their Big Five-O surgery at the same time. A very high percentage of Japan’s bridges were constructed during the period of high economic growth right after the war, about a decade after a public works building boom in the United States. In Japan, there are approximately 13,000 bridges built before 1960, but 41,000 built before 1970. This means that three times as many bridges will be hitting 50 in the coming decade.
The work of reinforcement and reconstruction will snarl traffic and soak up tax money, but it’s public work well worth the work. I just wonder if bridge maintenance can possibly get adequate funding given the money needed for reconstruction after the earthquake and tsunami of March 11. I was at the Ministry of Land, Infrastructure, Transport and Tourism on April 27 conducting an interview about bridges for my column in The Japan Times. My source told me that while a formal survey is still in progress, aging bridges that had already been reinforced appear to have held up very well in the Tohoku earthquake.
For more information on bridges in Japan, check out my May 17 column in The Japan Times. By the way, my monthly publication slot has changed from the third Thursday of the month to the third Tuesday.