I think this term "human factors" is what "usability" is called in the transit world. Here is an example: Improving Public Transit Schedules, Timetables People Can Actually Read Unfortunately there is still relatively little research of human factors and usability of public transit for the people that use the system.
Most of the "human factors" research in transit is for automobiles, very little seems to take the user of transit as a research subject. I would like to see much more work on users of transit, the lack of usability of transit stops, the lack of network route aids, the bad comfort levels, transit fare structure affecting usability and the debilitating affect that advertising in transit stops and vehicles has on the usability of the transit system. The few papers over the last five years have almost no effect on the usability of transit systems that remain incomprehensible, uncomfortable, inconvenient, annoying, sometimes dangerous and usually unusable for most of the population.
It is time to study why an advertisement on a transit stop is 5 feet by 3 feet and compare that to a bus schedule 4 inches by 8 inches without a map in a teeny font. Transit usability has extensive study about usability of transit web sites but very little on actual usability of transit modes themselves. A web site may let me see a route, but if the transit modes are unusable because of inconvenience, lack of comfort, expense or annoyances I will drive my car.
The lack of mass transit human factor studies is not a mistake, there is no money for trains, buses or other transit modes like bicycles and walking. Cars and trucks and airplane traffic get the bulk of the study money now but soon our society will be looking for a way to move without using a lot of oil. But why prepare for the inevitable?