There is a passing lane and not just on the street. There is a passing lane on sidewalks, on bike paths, in corridors and especially on the escalator at the airport.
The most important place to keep the passing lane open is the airport. Because sometimes, through a series of unfortunate events, a perfectly responsible, law-abiding citizen with careful planning habits, can be late for her plane.
If there are two escalators moving in the same direction and you want to plant yourself on one step, take the escalator on the right and let the people who come flying like bats out of hell with arms, legs and bags akimbo, pass by on the escalator to the left. If there is one escalator, stay to the right side and let them squeeze by you on the left. (There should be escalator signs like those road signs in Canada that say: “Squeeze Right.”) This means also moving your carry-on bags and other traveling companions to the right, too — on the stair above or below you.
If you need to get by some escalator squatters blocking the way, say “Please excuse me.” Have patience with parents traveling with small children. They get enough mean looks from everyone else.
From the Culture and Manners Institute at http://www.cultureandmanners.com

