We need to have a 'Allow Passing' check box in Astar in order to allow faster travelers to pass slower ones. Right now, faster people line up behind slower ones even when there is plenty of space to pass on either side.
This might not have been relevant before but now is with people models (I just made an hospital model where 10,000 person walk through during a day).
Depending how the programming is done, there could also be a parameter 're-check frequency' which would determine how frequently is the calculation done for any traveler. For example, by putting 5 seconds, it would mean that it's possible that a person will follow a slow one for up to 5 seconds before the calculation is done and he then passes.