Well, I'm not going to be good at giving you an exact time, but I would say "not long." The stops are quick because there is no ticket taking or buying on the SDX. People just step on and off using all doors. The stop at the Bonneville station is also quick, at least the week we rode it, because it did not pull onto the Bonneville ground but stopped across the street and went straight on. I'm going to guess 10m, but that is a guess.