Found this after about 10 seconds of googling “2017 CTA Holiday Train Arrives in the Chicago Loop” It is a real blue dress white dress thing. I think I see a bit of an effect when the train stops, but a very very slight one if any exists.
Impossible to tell because the person holding the camera starts walking just as the train stops.
As an aside, jerk can be caused by other types of acceleration–namely, gravity. If you let gravity bring your car to a stop when going uphill, not applying the brakes until you hit zero velocity, you will still feel a jerk. In this case, to avoid the jerk you must actually use the accelerator slightly at the last moment (in contrast to the usual case on flat ground, where letting up on the brakes slightly is sufficient).
You may feel a slight backwards movement. See Draft Gear movements. Moving and Improving the World
Though addressing freight cars; passenger cars may also have draft gear mechanisms. Freight cars that handle shock sensitive cargo will have great movement to absorb starts and stops.
Ed Norton reading newspaper to Ralph Kramden:
Train Stops With Jerk
Jerk Gets Off
Aside: I was on a train ride yesterday (the Cuyahoga Valley Scenic Railroad), and I remembered this thread. At the last stop, I set my phone to produce a graph of three-axis acceleration vs. time, and braced it against the armrest. To the limits of my phone’s ability to measure, the Y acceleration went from constant positive to constant zero, without any overshoot at the moment of stopping… but the stop was pretty gentle, such that the noise in both constants was comparable to the change in acceleration, so it’s not as definitive an experiment as I’d have liked.
This is why this place fascinates me.
It’s direct access to the raw output of all of the sensors on a phone.