It’s probably the number one gripe about tourists: they stand on both sides of the escalators on Metro, blocking the left side that is generally understood to be for walking. We Washingtonians understand that you stand to the right and walk on the left– there are even Facebook groups and t-shirts supporting the concept– but there are no formal signs on or near the escalators that say so. Why not? Rumors range from the theory that having people walk on one side and stand on the other leads to an unequal balance of weight and causes escalators to break down more frequently, or the theory that Metro doesn’t want to formally endorse a ‘stand right/walk left’ policy for liability and safety reasons. But what’s the real reason there aren’t signs telling tourists to stand to the right?