Engineers in the US this week seized on the catastrophic collapse of part of the MacArthur Maze interchange in San Francisco to stress the vulnerability of the nation's highway infrastructure.
The interchange, which feeds 75,000 motorists a day onto the San Francisco-Oakland Bay Bridge, collapsed in the early hours of Sunday morning after a petrol tanker crashed into a central pier and burst into flames.US engineers said the crash highlighted the absence of redundancy on some of the nation's key transport corridors and reinforced the need for urgent investment.The US Congress is currently consulting on a new national transport policy, the first since the interstate system was introduced by President Eisenhower in 1955. Dean Bowman, member of the American Association of State Highway and Transportation Officials Highway Working Group who is drafting highways component of the strategy explained the need for more investment.'Most interstate bridges were built between 40 and 50 years ago, so in the next few years the number of bridges over 50 years old is going to increase dramatically. The gap between need and investment is getting bigger.'