When he said, "We don't have enough females," Mr. Costello cast doubt on the accuracy of everything else he said.
In economic terms, a truck driver is a truck driver is a truck driver. It doesn't matter whether he's a man or she's a woman or they're from Mars. They are all "Logistics Input = Truck Driver."
The age of the truck driver matters, just as the age of the truck matters, because an older unit will have more downtime and need replacing sooner than a newer one. However, the sex of the truck driver matters no more than the color of the truck.
It depends on the job. Local P&D requires freight handling, a skill most woman are physically unable to acquire.
Really, how many women do ya see unloading/loading trucks/strapping down/securing loads on flatbeds etc, as well as driving 500 miles a day?
There's another point here, I think. They're short a lot of bodies, and they have very little participation by one-half the labor force.
If the industry could somehow change that, it would have a profound effect.