August 2, 2007
Original blog post
The catastrophic collapse yesterday of a worn down, 40-year-old, 1,900-foot-long bridge with a single steel arch at its center, spanning Interstate 35W across the Mississippi River in Minneapolis had as of this morning resulted in four deaths, up to 30 people unaccounted for, and at least 79 more injured - some quite severely. The fatality toll is likely to grow. Very recent maintenance work on the bridge had focused on joints, lights and guardrails, and resurfacing work was being done on it when it failed. The cause of the collapse is unknown and will remain so until an investigation is completed. However, it can come as little comfort that, as the Associated Press notes in a report today from Minneapolis, the feds identified the bridge as "structurally deficient" in 2005. Yet it turns out that term is considered by many officials to be less alarming than it sounds.
The bridge had been inspected by the Minnesota Department of Transportation in 2005 and 2006 and no immediate structural problems were noted, Gov. Tim Pawlenty said Wednesday. A federal database, however, showed the 40-year-old bridge had been rated as "structurally deficient" in 2005 and possibly in need of replacement, the (Minneapolis) Star Tribune reported citing the U.S. Department of Transportation's National Bridge Inventory. The White House also confirmed the 2005 inspection. White House press secretary Tony Snow said the span rated 50 on a scale of 120 for structural stability. "This doesn't mean there was a risk of failure, but if an inspection report identifies deficiencies, the state is responsible for taking corrective actions," he said.
Jeanne Aamodt, a spokeswoman for the Minnesota Department of Transportation, said her agency was aware of the 2005 assessment. She noted that many other bridges around the country carry the same designation and declined to say what the agency had done to address the deficiencies.
Lowered expectations for bridge condition standards and repair funding is well-integrated into governmental rubric. In the The Federal Highway Administration's "Status of the Nation's Highways, Bridges and Transit: 2006 Conditions and Performance," the report's authors state in Chapter 3 that:
Two terms used to summarize bridge deficiencies are "structurally deficient" and "functionally obsolete." Structural deficiencies are characterized by deteriorated conditions of significant bridge elements and reduced load-carrying capacity. Functional obsolescence is a function of the geometrics of the bridge not meeting current design standards. Neither type of deficiency indicates that a bridge is unsafe.
Got that? "Deteriorated conditions of significant bridge elements and reduced load-carrying capacity" does not indicate that a bridge is unsafe. What a relief!
Call it "defining deterioration down." According to the report, as of 2004, 26.7 percent of the nation's bridges were either "structurally deficient" or "functionally obsolete." It wouldn't do to have one-quarter of our nation's bridges considered unsafe: that would raise the scepter of malignant neglect.
The Seattle Post-Intelligencer this morning reports that in a 2005 study, the American Society of Civil Engineers found that 26 percent of Washington state's 3,000 bridges also earned the classification of "structurally deficient" or "functionally obsolete."
Of the state's bridges, (Washingtoon State Department of Transportation chief bridge engineer Jugesh) Kapur said two -- the (Alaskan Way) viaduct and the Evergreen Point Bridge, which crosses Lake Washington as part of state Route 520 -- cause him the most concern. "Those two keep me up at night," he said. Six years ago, engineers determined that a magnitude 6.5 earthquake in the wrong spot could collapse the Evergreen Point Bridge and the viaduct.
....The city and state remain at an impasse over the elevated structure's future and a possible replacement option. A $4 billion-plus initiative is planned to replace the Evergreen Point Bridge. Studies have shown that the bridge wouldn't survive a catastrophic earthquake and could also sink in a windstorm. A review panel -- mostly lawyers and engineers appointed by Gov. Chris Gregoire -- has advocated decisive action. "The existing viaduct and bridge will continue to deteriorate and inch closer to catastrophic failure" until a decision is made, panelists wrote in a September report.
Richard Miller, director of roadway structures for Seattle, said Wednesday that several of the city's 180 bridges need to be replaced, most notably the Magnolia Bridge. Miller said the city Transportation Department is reviewing several design options for a new Magnolia Bridge. Construction of a new bridge would likely start no earlier than 2009. Several South Seattle bridges are also in need of repair or improvement, Miller said. The Airport Way South Bridge is being help up by temporary supports, and several other smaller bridges are due to receive seismic retrofits.
WSDOT in April released a YouTube a video simulation of the 44-year-old SR 520 bridge collapsing in an earthquake. The $4.4 billion question is whether political leaders can summon the courage to fully fund the replacement sooner rather than later, something which will require tolling not only on 520 but also I-90.
The national problem of bridge safety carries a daunting price tag. In Chapter 7 of the FWHA 2006 report, the agency warns that merely to keep travel time, operational and crash costs from deteriorated bridges at their current (2004 constant dollar) level through 2024 will cost $78.8 billion; and to actually reduce such infrastructure-related costs in the same time frame would cost $131.7 billion in improvements, including increased local, regional and state user fees or taxes.
In its "Report Card For America's Infrastructure," the ASCE gave our nation a "C" grade for the condition of its bridges, and in that section adds:
Solutions intended to ease the increasing demands on our transportation system and to improve highway conditions, capacity and safety are multifaceted, and do not always mean simply building more roads and bridges. America must change its transportation behavior, increase transportation investment at all levels of government, and make use of the latest technology. Cities and communities should be better planned to reduce dependence on personal vehicles for errands and work commutes, and businesses must encourage more flexible schedules and telecommuting. By 2010, all levels of government should ensure that fewer than 15% of the nation’s bridges are classified as structurally deficient or functionally obsolete (itals in original).
As Cascadia Center pointed out in this 2005 Puget Sound Business Journal op-ed, the federal Highway Trust Fund generated via the federal gas tax and additional fees is increasingly insufficient for repairs and improvement of major transportation infrastructure.
Now in Washington state, political and business leaders and policy experts need to join with voters to build trust in transportation system management, funding and decision-making. That means an end to balkanization in transportation governance. That means developing a shared vision of convenient, fast transit options needed to dramatically boost actual transit usage. And that means innovative financing of necessary road and bridge repairs or replacements using tools such system-wide time-variable tolling on major highways, and public-private partnerships.
Let's not wait for one of our bridges to collapse before we get moving.