When is it legal to use a handheld mobile device while driving?

Using a handheld mobile device while driving is permitted in cases of emergency only, reflecting the understanding that the primary focus while driving should be on the road and safety. Emergencies may require immediate action that could necessitate making a call or sending a message, and the law recognizes these situations as exceptions where a driver must be able to communicate without delay.

The other options suggest scenarios where using a handheld device is not aligned with best practices for safe driving. Stopping at a red light does not mean it is safe to engage with a mobile device, as it could lead to distraction when the light changes. Likewise, using a device whenever driving increases the risk of accidents due to distractions that take the driver's attention away from the road. Even hands-free mode, while safer, is not permitted in all situations as the device could still distract the driver mentally, which is why the emphasis is placed on using a device only during emergency situations.