When is it illegal to use a cell phone while driving a commercial vehicle?

Using a cell phone while driving a commercial vehicle is illegal at all times unless the driver is using hands-free technology. This regulation is in place to ensure the safety of both the driver and others on the road, recognizing that the use of handheld devices significantly increases the risk of accidents due to distracted driving. Hands-free technology allows drivers to maintain control of the vehicle while still being able to communicate, thereby reducing distractions.

The other options suggest circumstances where cell phone use may be legal, but this does not align with the regulations governing commercial drivers. For example, using a cell phone while carrying passengers may seem relevant, but the law broadly prohibits handheld use regardless of passenger status to promote overall road safety. Similarly, the prohibition is not limited to certain areas like construction zones or restricted to nighttime driving, as distractions can occur at any time and in any location.