I wonder if someone has ever done an experiment where they have slowed the escalator way down to see if that encourages people to either take the stairs or walk up the escalator while its moving. I know that when I see a crowded slow escalator I don't want to waste my time so I use the stairs if available. People seem to be motivated by their surroundings too. During the sales after Thanksgiving there seems to be more running up and down stairs for those who are able. I think you have hit on the key here with music and lights and thats there needs to be some sort of motivation to change habits. The musical stairs, to me, is an intrinsic as well as an extrinsic reward.