Northbound lanes were opened at 5:15 p.m., while southbound lanes reopened at 11:54 p.m.
A Caltrans representative said the pavement underneath the collapsed bridge was in good shape. Crews worked on sweeping and re-striping the roadway.
The bridge caught fire at about 1:30 p.m. Monday. At least one worker cutting rebar with a cutting torch ignited a wooden section of the bridge, according to the San Bernardino County Fire Department.
Workers tried to put out the fire, but strong winds up 35 mph caused the flames to blow out of control and made it difficult for firefighters to extinguish the fire.
Some sections from the bridge fell onto freeway lanes and forced lane closures, causing traffic to back up for nearly 20 miles.
Firefighters worked Tuesday on dismantling the bridge a chunk at a time to reach the remaining flames.
The bridge project began last year. Damage from the fire has not yet been assessed.
