Probing A Traffic Congestion Controversy: A Comment

Ohta (2001) claims to have resolved a die-hard controversy on traffic congestion modeling by defining an inverse aggregate demand function that has traffic density as its argument—in Ohta's terminology the 'primitive term.'Using this demand function, Ohta shows that 'hypercongestion' may very well be an optimal stationary state. This contribution argues that at least if what road users demand is completed trips, and if time spent on the road while traveling implies a cost, then Ohta's approach is fundamentally flawed. Also the conclusion that hypercongestion can be optimal is no longer valid.