This seems to rely on assuming that the average time taken is the metric to optimize.<p>Imagine that you have 100 passengers, 25 of which aren't concerned with time taken, 50 of which are indifferent, and 25 of which are concerned with time taken.<p>With a 'walking lane', it seems to me that everyone is satisfied.<p>Without a walking lane, average speed improves, but those that would prefer to walk are slowed down.<p>I can't speak for others but I personally find the system excellent. If I'm in a rush, I can run up the stairs. If I'm not, I can chill.<p>I would generally be in favour of asking everyone to walk (as the below poster mentions), but that can't be expected of everyone - the disabled, elderly, children, those with suitcases, and likely other groups can't do that.