Yes, you can. If everyone is walking to a centralized transit location, then those that would like to know each other will easily identify themselves. Catch the bus at 8AM? You'll soon learn who else is walking that route. Headphones or not, human interaction isn't that awkward. Even if you never talk in that context, it only takes one out-of-context interaction to end that. At a coffee shop: "hey, don't we walk the same route from the metro every day?" or "Didn't i see you at the farmers market on Thursday?"

To know people locally, you need to live locally. If getting dinner involves a commute, then you're never going to meet people. It takes more than one or two instances to get past the earbuds. Remove the automobile and immediately you're seeing the same people dozens of times a week.