2 way radios operate on higher frequencies than CBs do.
Those little hand held units that we see on the market that are the size of small cell phones have a range of about 2 miles and operate on lower frequencies than 2 way radios. Haven't a clue as to range on those CB units mounted on/in the dash like truckers use.
Those large convoy trucks should be equipped with dash board mounted 2 way radio systems as standard equipment.
But there again they DEPEND on 2 way radio transmission/repeaters towers for relay of transmissions.
Aye, these guys are HET drivers from the sound of it (and from what they're hauling). I know it's been five years since I got out but it would've been unusual for every truck in a convoy like that to have a radio. I was never in a unit where the support platoon had radios in each HEMTT or Five Ton.