Ghosts of motion

An escalator leading into the Union Station Metro stop is broken. This means that the other one is shut off so that people can walk up one side and down the other. What's interesting about the process isn't the care I take to avoid being pushed back down by the people coming down as I go up, it's noticing the way that my muscle memory assumes the escalator is moving and I feel myself almost slip forward as I step onto it. It's as if the machine is so used to going in one direction that it leaves a ghost of that motion behind even when it's turned off.