Drivers were still advised as of about 5 p.m. to prepare for massive delays due to the spill, which occurred when the truck's two trailers malfunctioned, CHP Officer Eric Anderson said.
Officers responded to reports of a sand spill on the Bay Bridge near Treasure Island at about 2:15 p.m. A Sig-alert was issued when officers arrived, Anderson said.
Sand spilled in a 10- to 50-foot line along the two far right lanes of the highway, and three lanes were closed while the spill was removed, Anderson said.
Crews initially estimated it would take an hour to clean the sand off the roadway, but technical problems prevented a sweeper from getting to the highway. The lanes weren't fully reopened until 4:50 p.m., Anderson said.
"It was just an unfortunate accident at an inconvenient place," he said.