That doesn't sound right. You need 15-20 people to make up the weight of an average city car, nevermind a SUV or truck, plus 4+ passengers and load. That's a crowd of 30 for every car the bridge can support.
Yes, but you can pack the bridge more completely with people.[1] It's apparently an urban legend that the Golden Gate was in any danger of collapsing when people were allowed to walk on the roadway for its 50th anniversary--but it may well have been a peak load.
“It was probably the biggest load the bridge had ever seen,” said Mark Ketchum, a San Francisco bridge engineer who studied the Golden Gate Bridge from 1989 to 1991. “But it did not exceed the design load capacity of the bridge.”
