rush hour traffic

Federal officials are sending engineers to find out what caused a repair on the San Francisco-Oakland Bay Bridge to fail and send a 5,000-pound crossbeam and two rods into rush-hour traffic.

The Federal Highway Administration sent engineers Wednesday to investigate what caused repairs to fail on the San Francisco-Oakland Bay Bridge and drop 5,000-pounds of metal into rush-hour traffic lanes.

The agency said it had not inspected the Labor Day weekend repairs made to the heavily used span.

Drivers are spending less time stuck in rush-hour traffic for a second straight year,  as high gas prices and the economic downturn force many Americans to change how they commute.