Most likely cell phones or GMRS now.
Unless with same local company, cell phones are used to talk to friends, etc, who may be many states away.
I’m not aware of anyone using GMRS (haven’t heard conversation about such), but I’d not rule out any service.
Oversize (heavy haul) often is on 2-Meter, but that’s to keep convoy alerted, not aimed at non-involved drivers.
A year or so back I ran a scanner on continuous AM scan and found that of the forty regular channels
some areas of the country had truckers and non-truckers on channels other than 19 (quite a bit; WV, for example).
Again,, you’ll need
a very good scanner antenna to uncover 11-Meter activity. A suction cup string IS NOT that antenna.
A PRESIDENT
McKinley or
Randy used in scan mode would be better than most scanners. (U-980 also).
TIME OF DAY: is crucial. Truckers are looking to get their loads delivered and are focused pre-dawn till late morning.
As the afternoon wears on, chatter will die down to almost nothing unless regulars are passing friends. Everyone’s tired and getting in the final miles of the 4, 5, 600 needed that day. Only wrecks and other problems brings them back.
My day may start at 0400 and be over by 1700 (I’m parked and eating dinner; ready for bed). You leave work at 1700 to drive home you might not hear much at all. Nothing. Same for weekends. Etc.
With this said YOU NEED A VERY GOOD ANTENNA SYSTEM (mobile or at a base) to capture that distant, often faint TX that IS out there M-F especially 0400-0900 anywhere near metro areas, or sea, river and rail ports. Oilfield. Farm harvest. Etc.
I’m not suggesting EXPENSIVE, but well-designed & installed.