I tend to get on the train at South Station, because it is marginally closer to my work than Downtown Crossing. However, "closer" is a description to be taken under advisement, because Downtown Boston is a tiny, tiny place. The three main stations (all three have transfer options) are so close together it's really not worth it to wait for a train from one line to another if all you need is to transfer from the Red Line to the Orange (at Downtown Crossing) or Green (at Park Street) Line.
And here we pause for visual aids:
The South Station-Downtown Crossing-Park Street trifeca is pretty much in the center of the map. See those black lines between Park and Downtown Crossing? That's telling you there's a tunnel which allows you to walk between these two stations. That's how close they are.
From South Station to Park, it's a 10 minute walk. If it's a nice day (ie, not a blizzard), it's usually faster to walk than to wait for a Red Line train to take you to the line you want. I often walk to Park if I have nothing better to do, because it's not that far, and it makes my ride to Cambridge shorter. And I'm only taking the Red Line.
Today, I got on the train at South Station. Today was a nice day; I could have easily walked to Park, but since I'm going all the way to Harvard Square anyway, it doesn't matter that much so I opted for the closer station. I managed to get on a train at 5:35pm. This train was mostly empty, but I made the mistake of getting on a car right by the stairs to the platform. The train sat there for at least 10 minutes.
And, of course, everyone comes charging down the stairs and flings themselves on the train because, OMG the thing will be leaving any SECOND. Except it isn't. It's sitting there. For at least 10 minutes. I timed it. People are shoving their way onto my car, desperate to get to their destination.
Finally, the doors shut, and the trains starts moving. It takes a minute, at most, to get to the next station, Downtown Crossing. But here's the thing. Half the people who forced their way bodily on the train? Got off at Downtown Crossing. They waited 10 minutes to ride a minute to a station that only takes 5 minutes, tops, to walk to. Where they, no doubt, had to wait for the Orange Line train.
More people got on at Downtown Crossing, desperate after waiting 10 minutes for the Red Line train. Only to do it again...over half of them gor off the train at Park. Park Street is even closer to Downtown Crossing than South Station is...as I pointed out, they're actually connected.
Which is why I hate people. They'd rather stand on an overfilled train, barely able to breathe, for 10 minutes waiting to be carried to the station where they can catch their train for home...instead of walk to the station they actually need.
Because heaven forfend anyone should actually walk anywhere in this day and age.
Note to self: Start catching the train at Park Street for the summer. At least then you only have to deal with Cambridge idiots, who are at least, on the whole, better educated. Or, better yet, just walk all the way home; it only takes a little over an hour.