The bottleneck is usually the plant, not the road
Operators focus on transit time because it is visible. In bulk movement the larger and more variable component is frequently the time spent inside the plant.
Splitting the cycle into queue-to-load, loading, transit, queue-to-unload, unloading and return shows where the hours actually go.
That split is what converts a general complaint about turnaround into a specific one about a particular plant, gate or shift.