When is it illegal to use a handheld mobile device while driving in Montana?

In Montana, it is illegal for drivers under the age of 18 to use a handheld mobile device while operating a vehicle. This law is designed to protect inexperienced drivers who may be more easily distracted and thus at a higher risk for accidents. The restriction aims to promote safer driving habits among younger drivers and reduce the likelihood of distracted driving incidents.

While other choices mention different conditions under which mobile device usage might be restricted, the specific prohibition for drivers under 18 is a focused legal measure intended to enhance safety in this demographic. Thus, this answer reflects a clear understanding of the laws in place for novice drivers who are still acquiring their driving skills.