(Reuters) - Construction crews are making quick progress repairing a busy Delaware commuter bridge closed down earlier this month because some of its support beams were tilting, state transportation officials said on Thursday.
The shuttering of the I-495 bridge over the Christiana River near the city of Wilmington has caused massive traffic delays in Pennsylvania, New Jersey and Delaware.
"Work on repairing the I-495 bridge is rapidly moving ahead," Delaware's Department of Transportation said in a statement but provided no timetable for the bridge's reopening.
The bridge, which carries some 90,000 vehicles daily, was closed when engineers performing a routine survey found four of its 37 pairs of support columns tilted by as much as 4 percent.
The bridge was closed indefinitely, with no firm timeline as to when it would reopen. Its closure prompted the statewide inspection of other key traffic arteries, transportation officials said.
Earlier this year, a report concluded that more than 63,000 bridges across the United States are in urgent need of repair, with most of the aging, structurally compromised structures part of the interstate highway system.
The dangerous bridges are used some 250 million times a day by trucks, school buses, passenger cars and other vehicles across the country, according to the survey by the American Road and Transportation Builders Association.
Reporting by Victoria Cavaliere; Editing by Bill Trott