It’s important to take note of the time when the plane doors are closed. Then, if the wait feels like it’s getting a bit longer than normal, you can measure how much time you’ve been sitting on the tarmac. If the wait is too long, there’s something you can do. In the USA, laws say that tarmac delays over 2 hours require special attention. Food, water, and operational lavatories must be made available to passengers, as well as medical care, if required. If the delay goes on over 3 hours passengers should be offered the opportunity to deplane.