Apple knows exactly where you are, how fast you've been traveling and how much distance you've traveled. If you've been standing in a field for the last 40 min

Apple knows exactly where you are, how fast you've been traveling and how much distance you've traveled. If you've been standing in a field for the last 40 minutes, and haven't traveled more than 10 meters at a slow pace, and are surrounded by hundreds of other iphones that also have barely moved, you probably aren't suddenly in the middle of a car crash.