This isn't the first time I've seen it on BART. It's not a bad idea and there are actually quite a few styles of portable seat options out there. Would you ever use one? Would it ever become popular on BART? People stared at this man, but why? He's comfortable, he's not taking a ton of space, at least no more than a person with a large backpack. I can't imagine this being the norm on BART but why not? And what IS the norm on BART anyways??