Here’s a great article in The Millions about writing while riding the subway. This is how I’ve gotten a lot work done over the past few years. I think, as they’re saying, the main reason is not enough hours in the day. The other is to ward off the solitude at a desk in an apartment someplace. It’s not always ideal—sometimes there’s just too much goin’ on to really write well. But a lot of times, it’s the perfect environment.