Train Eating

I know people are in a hurry, but I still don't understand why they would opt to eat on the train. The subway isn't the best way to eat your lunch. Wouldn't it be better to take a few minutes to snarf down your McDonald's hamburger outside?

And speaking of train eating and McDonald's, I watched a girl chow down a Chicken Sandwich on my way home from the gym today. Not only that, she consumed the sandwich in less than three minutes - not even taking a breath between bites. Which made me think: when I eat, do I chew, then swallow, before taking the next bite?