You have to first analyse the loads on the beam itself to make sure the beam size can take the loads, then you have to analyse the bottom flanges of the beam to make sure they don't bend excessively as the wheels travel.
I'm an EIT here in canada working for a small sutrcutrla engineering firm. We don't have many people working for us, myself, one other engineer (licensed) and two draftsmen. As such I am frequently completely in charge of entire projects (with the engineer checkig my work, of course). However...
