The group made their way on eastbound and westbound lanes of state Highway 92 on the bridge at the high-rise around 4:50 p.m., CHP Officer Daniel Hill said.
The protesters had been dropped off by cars on westbound lanes and briefly made their way to both sides of the freeway, he said.
As of shortly after 5 p.m., eastbound lanes were reopened for motorists heading to Hayward but westbound lanes were still closed off for cars traveling to Foster City, Van Eckhardt said.
There were 30 CHP patrol units sent to the bridge to clear the protesters, Van Eckhardt said.
Around 5:15 p.m., the far left lane on the westbound side was reopened to traffic, CHP officials said.
The group was given the opportunity to leave the scene peacefully, but 68 people who didn't comply with orders from officers were detained, Hill said.
As of about 6:10 p.m., the arrested protesters were still on the bridge waiting to be transported to San Mateo County Jail, according to Hill.
They are expected to face charges of disobeying a lawful order of a peace officer and obstructing the free movement of others, Hill said.
The protesters were peaceful and did not become violent, according to Hill.
Two other westbound lanes remain closed until 6:40 p.m. but traffic remained heavy on the bridge, CHP officials said.