The feature does exactly what you expect: It keeps all those pesky alerts from appearing on your screen while you're behind the wheel. The software uses Bluetooth or WiFi doppler effect to determine how quickly you're moving. If you attempt to view your screen while in motion, you'll be greeted by a blank screen.
After you've used the feature once, it'll prompt you to launch DNDWD when it determines if you're in a moving vehicle. You can dismiss the notice by saying you're a passenger.
Once enabled, the feature also auto-replies to texts with a message that you're driving. There is also the option to whitelist certain contacts and they'll have the option to text back "urgent" to display their text regardless if Do Not Disturb While Driving is running.
The new option is Apple's way of making the iPhone more car and safety friendly when the driver doesn't have access to CarPlay.
Lastly,Apple updated its Maps app with lane guidance so drivers are alerted which lane they should be in for things like exiting the freeway. The company also added detailed indoor Mall and Airport maps so you can find your gate and the nearest Sbarro.
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