California ? The freeway that collapsed after a fiery tanker crash has reopened just 25 days after the accident, though one expert questioned the safety of the new structure.

The elevated section of highway that carries traffic from the east end of the San Francisco-Oakland Bay Bridge was leveled April 29 after a gasoline tanker truck crashed and burned. Officials and commuters initially thought it would take weeks, possibly months, to fix.

But traffic exited the bridge Thursday night and cruised for the first time over a new 165-foot stretch of highway.

Department of Transportation officials maintain the rebuilt structure is sound.

But Abolhassan Astaneh-Asl, a civil engineering professor at the University of California, Berkeley, questioned that assertion. He argues that Caltrans should replace the structure’s four supporting piers, which he said were also damaged during the 1989 Loma Prieta earthquake.