TOKYO — The deadly collapse of hundreds of concrete ceiling slabs in a tunnel outside Tokyo is raising calls for more spending on Japan’s aging infrastructure, but the country simply might not have the money.
Nine people were killed Sunday in the tunnel, a major link between the capital and central Japan that opened in 1977 at the peak of the country’s postwar road construction boom.
Police searched the tunnel operator’s offices Tuesday, looking for evidence of negligence.
The Transport Ministry has ordered inspections of 49 other highways and road tunnels of similar construction in the mountainous country.
Much more of Japan’s transportation system may require refurbishing after years of spending cuts that have starved projects of funding, including those needed for basic maintenance.
The Infrastructure Ministry, which is in charge of land and roads, joined with three government highway operators last month to form a panel on how to handle problems of deteriorating expressways and tunnels.
Analysts told the panel that about 40 percent of the 5,415 miles of expressways the agencies oversee had been in operation for more than 30 years, the Yomiuri newspaper reported Tuesday.
The newspaper cited Toyoaki Miyagawa, a structural materials engineering professor at Kyoto University, as saying that countermeasures are “urgently needed” because the roadways and tunnels were built according to specifications suiting much lighter traffic loads than today’s.
Such projects would pose an extra burden at a time when Japan’s public debt already has soared to more than 200 percent of its gross domestic product.
Mr. Miyagawa said Sunday’s tunnel accident likely resulted from a faster-than-anticipated aging of the structure.
About 270 concrete slabs collapsed onto the roadway deep inside the Sasago Tunnel 50 miles west of Tokyo, falling on three moving vehicles.
Central Nippon Expressway Co., the tunnel’s government-owned operator, said it had no record of any major repairs performed since the tunnel opened, but company official Satoshi Noguchi said an inspection of the tunnel’s roof in September found nothing amiss.
About a dozen uniformed police were shown on television Tuesday entering the company’s headquarters in the central city of Nagoya, toting cardboard and plastic boxes.
“Yes, they are searching our offices here. We will be fully cooperating with them,” said Osamu Funahashi, another company official.
The slabs, each weighing 1.54 tons, fell over a stretch of about 120 yards. The operator was exploring the possibility that bolts holding a metal piece suspending the panels above the road had weakened with age.