Theory 16/The rival is a different mechanism/Traffic
Instability or Just Demand?
The claim
Traffic flow breaks down because the flow state becomes unstable near capacity.
01The rival explanation
Congestion is simply too many cars: the relationship is demand-driven and monotonic, with no instability.
02What would tell them apart
Instability predicts breakdown from small perturbations at identical demand, producing scatter that demand alone cannot explain.
03Prediction
Breakdown should occur at variable demand near capacity.
04Refutation
If breakdown occurs at a fixed demand threshold, the rival wins.