Why the lane is the unit and the average is the trap
Freight pricing briefs usually ask for a national rate. It exists, it is published, and it is close to useless for anything operational.
Truckload pricing is a lane market. A lane out of a tight origin prices nothing like a lane into one, and the imbalance between directions is what determines whether a carrier will take the load at all. National averages hide that completely, and the lanes a shipper actually runs are the only lanes that matter to them.
The second trap is the spot and contract blend. These are different commitments with different risk, and the spread between them over time is a read on where the market is heading - narrowing when capacity tightens, widening when it loosens. Merged, the spread disappears and so does the signal.
The third is fuel. A rate that includes fuel surcharge moves when diesel moves, which has nothing to do with freight demand. Recording the convention lets an analyst strip it out; not recording it guarantees somebody eventually explains a diesel spike as a demand surge.
The fourth is that published benchmarks are aggregates of transactions, not quotes for your freight. They describe a market and they are not a price you can hold anybody to - we say that plainly rather than letting a benchmark be read as an offer.