 |
|
|
 Editorials | August 2007 
A Bridge Collapses
 The New York Times
go to original
| | Abandoned cars sit on the rubble of the Interstate 35W bridge in Minneapolis, Saturday, Aug. 4, 2007. The eight-lane bridge, a major Minneapolis artery, collapsed over the Mississippi River during the evening rush hour Wednesday. (AP/M. Spencer Green) |
The nation's physical foundations seem to be crumbling beneath us. Last week, a 40-year-old interstate highway bridge collapsed in Minneapolis, plunging rush-hour traffic into the Mississippi River 60 feet below. Two weeks earlier, an 83-year-old steam pipe under the streets of Manhattan exploded in a volcano-like blast, showering asbestos-laden debris. And two years before that, substandard levees gave way in New Orleans, opening the way for the floodwaters of Hurricane Katrina.
These are some of the most dramatic signs of the nation's failure to maintain and enhance its aging physical structures at a time when demands on roads, transit systems, sewage treatment plants and other vital facilities are rising. In the event of a catastrophic failure, many lives can be lost. But even the slower deterioration undermines our quality of life and retards economic growth. Traffic jams waste gasoline, pollute the air and exhaust drivers' patience. Disabled trains and subways strand commuters. Gridlocked airports disrupt travel plans. And power failures plunge millions into darkness.
At a time of ballooning deficits, and in the midst of a hugely expensive war, most politicians will be tempted by the quick and inexpensive fix. But that is exactly how the country got into this problem.
How large a challenge the country is facing can be seen in a report by the American Society of Civil Engineers, grading the nation's infrastructure. The latest report, issued in 2005, assigned a cumulative grade of D, down from D+ four years earlier. Near-failing grades of D- applied to drinking water, sewage treatment and navigable waterways. The highest grade, C+, went for landfills and the recycling of solid waste.
In between were unsafe dams, whose number was rising faster than they could be repaired; overstressed power lines, whose maintenance budgets had decreased for a decade; public parks and beaches that were falling into disrepair; and deteriorating schools that seemed unlikely to accommodate rising enrollments or allow smaller classes.
Bridges actually scored relatively well, earning a straight C, mostly because the percentage of the nation's 590,000 bridges that were rated structurally deficient or functionally obsolete had dropped slightly, to 27 percent. The deficiency rating does not mean a bridge is in danger of collapse, but it does reflect the need for repairs, close monitoring and perhaps weight restrictions.
No one yet knows what caused the Minneapolis bridge, one of those deemed structurally deficient, to fall apart. Theories include undetected cracks or metal fatigue, vibrations from a resurfacing project on the roadway, or possibly soil erosion around the underwater supports.
The design of the structure was almost certainly an element. The 1,900-foot span lacked much redundancy for its critical supports, which could allow a single failure of a crucial structural part to bring down the whole edifice. The notion that critical parts ought to have backup systems seems so basic to current engineering practice that it is shocking to learn that some 756 bridges of similar design around the country also lack redundancy. They will need to be inspected and monitored with great care.
Unfortunately, the adequacy of current inspections is also in question. It is disturbing that the pipe that burst in Manhattan had just been inspected and declared sound by a utility crew, that the levees in New Orleans had been regularly inspected by the Army Corps of Engineers, and that the Minneapolis bridge had been inspected annually.
In these and other failures it will be important to establish whether the inspectors failed to do a diligent job or whether the real problem is that inspections are inherently limited in what they can detect. Perhaps inspectors need to be given much better sensing equipment to detect hidden flaws.
The larger problem of crumbling roads, bridges and levees and crashing electrical grids can almost always be traced to a lack of investment. When budgets are tight, elected officials find it convenient to cut back on maintenance and leave some future administration to deal with the consequences. When Congress appropriates money for public works, the legislators typically prefer shiny new projects that will enhance their reputations, not mere maintenance on a bridge named after someone else. The federal government has particularly lagged in paying for infrastructure projects, leaving state and local governments to assume the dominant role.
Congress is now scrambling to provide extra money to help Minnesota replace its stricken bridge and is planning hearings on broader infrastructure needs. One sensible bill that ought to be quickly passed would set up a commission to assess the state of the nation's infrastructure, set priorities, and recommend financing approaches. Another bill is proposing a new national bank to leverage both public and private investment for repair and new construction projects. Each time there is one of these tragedies, politicians briefly declaim the need for a major and sustained investment in the nation's aging infrastructure. But that enthusiasm quickly flags. The collapse of Minneapolis's Bridge No. 9340 is a reminder that such long-postponed investments can no longer be neglected. |
| |
|
Vallarta Weddings
Tell a Friend
Site Map
Print this Page
Email Us