Hence why I don't forsee the capacity possibly being that high, but theortically, if the trains are only traveling 5 mph and they are traveling approximately a half mile, it would bacially take about 6 minutes from stop to stop. If there are 2 trains at 250 person capacities, then there are 500 people on the track at any given time.
With that, you would have 500 people on the track every 6 minutes, which is, 5000 people an hour, which is 100% doable, you could even have trains with 100 person capacities and have 200 people on the track at a time, and still have a 2000 person per hour capacity, which is very good.
So to me, if the train thing happens, it wont be a super long traditional train, but something smaller and more intimate.
(yes I re-did the number, and went to mapquesto to calculate the distance.