ANNAPOLIS (AP) — Maryland transportation officials yesterday refined their plans to conduct extra inspections on 10 deck truss bridges that have designs similar to the bridge that collapsed in Minnesota.
Joe Miller, chief bridge inspection and remedial engineer for the Maryland State Highway Administration, said he hopes to have six of the bridges under the agency’s jurisdiction inspected in two or three weeks. All six were inspected either this year or last year and found to be safe.
“None of them, based on the last inspection, showed any structural issues,” Mr. Miller said.
Three of the six were inspected last month, Mr. Miller said, so plans call for inspecting the other three first. The first to be inspected again likely will be the MD 32 in Carroll County. The other two are Interstate 495 over Northwest Branch, by the Montgomery and Prince George’s County line, and MD 144 over the Monocacy River in Frederick County.
A bridge inspection takes between one and three days, Mr. Miller said, often involving special trucks called “snoopers” that can lower an inspector over the side of a bridge to look underneath.
Because the National Transportation Safety Board has not found a specific cause of the bridge collapse in Minnesota, Mr. Miller said, the bridge inspections will be standard.
“It’s not specifically looking for one thing, unless more specific information comes out of Minnesota,” said a spokesman for the state highway administration.
Mr. Miller estimated a bridge inspection costs about $2,000 a day.
Meanwhile, officials in the District say they plan to fix 16 bridges rated as structurally deficient within the next five years, but that the city needs about $2.63 billion to cover the costs, officials said. Typically, 80 percent of the money would come from the federal government, but the city could have trouble coming up with its share.
“That’s an awful lot of resources for a jurisdiction the size of the District,” said Kathleen Penney, deputy chief engineer for the D.C. Department of Transportation.
A bridge typically is classified as structurally deficient by federal standards if heavy trucks are banned from it or there are other weight restrictions, if it needs immediate work to stay open or if it is closed. Such bridges are considered in need of considerable maintenance, rehabilitation or even replacement.
The 16 D.C. bridges listed as deficient according to the city’s most recent statistics represent about 6 percent of the city’s 245 bridges. That figure is down from 22 bridges classified as structurally deficient last year, according to statistics from the Federal Highway Administration.
Miss Penney said some of the city’s troubled bridges are counted as two because they have spans crossing in each direction or because a ramp to the main bridge is considered a second bridge on its own.
The highway administration rate nearly 1,200 of Virginia’s 13,357 bridges as structurally deficient. In Maryland, 410 of the state’s 5,059 bridges are listed.
The Interstate 35W bridge in Minneapolis was declared “structurally deficient” as early as 1990. At least five persons were killed and eight persons remained missing yesterday after the bridge collapsed during Wednesday evening’s rush hour.