Personally I like the European system. On German platforms you will see a diagram which each IC/EC/ICE train that stops on that track and a diagram of which cars are at which location. So you place yourself where you either have a seat reservation or where you want to ride.
I also think being allowed to wait on the platform definitely helps speed things up.
When I went up to visit my ex at Clemson, SC. Every evening we would spend it at the Amtrak station. So I sort of made my self the station master as it was an unstaffed station. I organized passengers by destinations and kept them informed on where to stand. What made that difficult though some conductors were good at spotting the train. While others spotted the boarding door three cars away from the only platform access point. I think the German H signs could be used instead of conductors spotting trains. Then every car should stop in the same place each time. And for the record when I was doing that at Clemson they could finish station work in about a minute
Considering that Amtrak changes the positions and number of cars, it would be difficult unless they spend the money for some dynamic electronics so at stations, one can find which car is one's assigned. It seems like crew spends an inordinate amount of time telling every passenger where they should board because the passengers have no idea where their car is even when they walk up to it (as the car's assigned number is tiny and is behind dirty, clouded covers whereas the number that identifies the physical car is high enough to read and has large painted numbers).
Wouldn't it be nice if there were electronic signs even at small stations that pointed to where sleeper, BC and coach passengers should stand because that info was either consistently the same or controllable remotely by an Amtrak employee with knowledge of that train's specific consist? But that would cost money and that's a problem. Of course, the train would need to stop at the same place every time.
