(a)(1) No driver shall use a hand-held mobile telephone while driving a CMV.

(2) No motor carrier shall allow or require its drivers to use a hand-held mobile telephone while driving a CMV.

(b) Definitions. For the purpose of this section only, driving means operating a commercial motor vehicle on a highway, including while temporarily stationary because of traffic, a traffic control device, or other momentary delays. Driving does not include operating a commercial motor vehicle when the driver has moved the vehicle to the side of, or off, a highway and has halted in a location where the vehicle can safely remain stationary.

(c) Emergency exception. Using a hand-held mobile telephone is permissible by drivers of a CMV when necessary to communicate with law enforcement officials or other emergency services.