The crash was reported shortly after 10:30 a.m. on southbound Highway 101 near the Brokaw Road off-ramp.
The Caltrans sweeper and a "shadow truck" behind it to protect it from traffic were traveling at about 5 mph south in the center divider of the highway, with the "shadow truck" partially in the far left highway lane, CHP Officer Ross Lee said. "It appears that the shadow truck was in its proper location, defending in a location to block the sweeping vehicles," said Lee.
A white Dodge Ram going about 65-70 mph in the far left lane then struck the back of the shadow truck. The Dodge driver died in the crash and his identity is not yet being released, Lee said. The truck was labeled T.W. Construction.
The CHP says a dog inside the bed of the truck was also killed.
The Caltrans worker has been taken to the hospital.
HWY101 UPDATE: SB lanes could reopen in 2-4 hours following fatal accident involving Caltrans vehicle. CHP says the driver in white pickup was partially ejected from truck. A dog inside the bed of the truck was also killed. Caltrans worker taken to hospital. @abc7newsbayarea pic.twitter.com/vH9zPd3G60— Carlos Saucedo (@Carlos_Saucedo) October 15, 2018
The crash prompted the closure of all southbound lanes of the highway, with traffic being diverted off on state Highway 87, according to Lee.
Before you head out the door, take a look at our real-time traffic map here.
ABC7 News Reporter Carlos Saucedo contributed to this report.