The allies had a similar problem during Operation Market-Garden in WWII. The two-lane highway we used was grossly inadequate, and every time a truck broke down, the column had to stop until the road was cleared.
Add to this the ground is thawing and turning muddy, making off-road travel difficult or impossible. I remember a REFORGER exercise in southern German in the late 70's, during a "heat wave." The strong foehn winds thawed out the ground and a company of tanks trying to cross a field sank to their turrets in the mud. It wasn't until April before they could finally dig those tanks out of that field.
I keep hearing the Russians are using cheap Chinese tires, which are failing under the wet and muddy conditions. I don't know how true that is, it's likely a lot of things that brought that 40-mile convoy to a halt. If I were an A-10 pilot, I'd be drooling over photos of that convoy.
