A camera device plus a brown shirt is all that is needed.
I never drove west of the Mississippi which is where it is supposedly most enforced, but big trucks cannot idle while a driver sleeps in cold weather to keep the heater on ... he has to have a separate, stand alone motor/generator for that purpose
Also ... west of the Mississippi you won't find a big truck pulled off to the side of a get on or get off ramp ... they must be in a designated truck stop
As I understand it, this has been active for about 15 years
Truckers confirm or correct me.