When can you legally use a cell phone while driving?

Using a hands-free device while driving is legally permissible because it allows for communication without requiring the driver to take their hands off the wheel or their eyes off the road. This approach minimizes distractions and helps maintain safe driving practices. In many jurisdictions, including Nevada, laws are designed to ensure that drivers remain focused on the road, and hands-free devices facilitate that by allowing voice commands or speakerphone functionalities.

The other options present scenarios that may lead to increased distraction and risk while driving. Holding a phone, for example, takes away a driver's ability to fully control the vehicle, while stopping at a red light does not exempt a driver from the potential distractions and unsafe behaviors associated with phone use. Permitting usage at any time during driving would compromise road safety, which is why regulations are in place to limit how and when mobile phones can be used.