They step over a $100 bill to grab a nickel....their world let em burn it down if they want...
Or maybe it's STILL cheaper to contract out a load, pay the driver who would have taken it a grievance, and not have to hire a full time equivalent for the entire year instead.
Due to eCommerce, peak is getting peakier, if that makes sense. Peak day is larger than a regular day by a bigger margin than it used to be.
We probably know we're going to have the loads. We know the drivers are going to grieve, and we know we're going to pay the grievance.
We know we have to provide the contractor with some certainty so they'll work with us, which means where we come up with fewer loads, drivers will stay home.
All of that is almost certainly cheaper than hiring another permanent driver, and buying / maintaining another tractor, which is the alternative. More like stepping over a Franklin to grab a gold bar.
And, I'd bet my paycheck all of this was discussed with the Union at a high enough level, and it's leverage for whatever else the Union can negotiate. The Teamsters are not unaware that there are contractors running loads. That's impossible.