FlightAware Discussions

Does the "planned route" dotted line change when ATC changes a flight's route?

I’ve noticed that the dotted blue line showing the planned route of a flight reflects the IFR flight plan filed. However, as I track a flight, I notice that the blue line will change shape occasionally when a flight is given a shortcut per ATC or otherwise deviates from its filed route. This doesn’t always happen, but I’ve witnessed it many times. How is the information on FlightAware able to keep up with ATC changes to a flight’s route without an actual change to the original flight plan? If any clarification is needed on the question, I can try my best to illustrate, and maybe provide some images.