Yes, that's correct about the vans. They'd purchase 1000 vans for the portion of the 8000 daily riders, at the time, who were regular rush hour commuters. Then they'd discontinue the commute trains. The also had another proposal around then to only run rush-hour trains, in which they could then also retire the harrimans since they had enough galleries for a reduced amount of trains.

While I pointed out that Caltrains has slightly more ridership than the peak of SP ridership around 1954, it is on far more trains. SP carried 16,000 passengers each way on 27 trains. Caltrain carries about 18,000 each way on about 45 trains each way. I think Caltrain carries far more off-peak riders these days. The big difference is rush hour. Back in the day, the SP had about 15 rush hour trains that just carried incredible loads. Each of the very 3 minutes trains (5:14-5:35) probably carried from 1000-1500 people. The others were anywhere from 6-10+ cars also. Now that demographic patterns have changed, there isn't that huge mass of people commuting by train into San Francisco.

By they way, I still don't believe that train 128 has 9 harrimans in that photo. Look at the pole that seperates the first six from the last three cars. I still believe the last three cars are on an adjacent track (perhaps for train 140, 5:45pm, which was also an all-harriman train). Train 128 pretty consistantly had 6 harrimans from the early 1960s through about 1976 when it dropped to 5 cars. 122, 128 and 140 were the all harriman trains from the early 1970 to the end of SP operations.