Why do you have to go up and down the stairs?
In general, there are railings on the left side of the stairs (upstairs). When the upstairs, the body is almost tilted forward, the chance of falling is very small, so go right, of course, go to the left also, so more insurance! Downstairs, if you run very fast, the body will tilt forward some, to fall when you can help the railing, to avoid this accident!
On the contrary, to the left, it will ... ... (and the above situation is the opposite)
Not rely on the right line, in the Commonwealth members and Japan and other countries on the left side of the country, we develop the habit of public places to travel is to walk in the left, as you said the upper and lower stairs is on the left line, these are not the law , But only we agreed to behavior.
This is related to the customs of different places, such as in China, driving is the right, but in the UK, then the left. Different regions have different habits, but this can also do a good job of traffic.
