Exactly. I walk because I'm strong and able to do so and it makes me more confident of getting to the train in time. They talk about increasing throughput by 30

Exactly. I walk because I'm strong and able to do so and it makes me more confident of getting to the train in time. They talk about increasing throughput by 30% but do we really want these things to be running at 100% capacity? I'd hate to have to pack in like a sardine and not have enough space to walk. Standing on one side seems to be a perfectly reasonable compromise.