A T-line train hit the van on Third Street near Underwood Avenue.
At least three people on the Muni car and four people in the van were hurt.
The tourists in the van say the driver got confused and made a sudden turn right in front of the rail car.
"I was scared the van was actually going to flip. I didn't know what was happening because I was laying down. I thought it was a real train, actually," said Joe Flannery, a van passenger.
The van driver suffered the worst injury -- a glass cut to his eye.
Muni set up a bus bridge until the accident could be cleared.