The collapse of the I-5 bridge over the Skagit River in Washington state Thursday night brings frightening memories of the deadly bridge failure near Minneapolis in 2007 and the collapse of the Mianus River bridge in Greenwich 30 years ago next month. And while the investigation in Washington is just beginning, the collapse also revives lingering questions about the quality and safety of the nation’s 600,000 bridges – including more than 4,200 in Connecticut.
Data from the Federal Highway Administration show that 9.6 percent of Connecticut’s bridges are considered “structurally deficient,” meaning one or more major components is deemed to be in poor condition, defined as “advanced section loss, deterioration, spalling or scour.” (Spalling refers to chipping or flaking of concrete and bridge scour is the phenomenon in which water currents wash away sediment, rocks or other material that surrounds the base of the bridge.) Highway officials caution that the designation of a bridge as structurally deficient does not mean the bridge is unsafe.
