How can the profitability of a transport infrastructure be evaluated ? The time used to be when growing traffic demand could be satisfied by building free roads, toll roads, railroads, and airports, all to the same destination, all at the same time, and with no need for overall optimization. Now, the infrastructure in France is at a level where each mode competes with the others.
So, finer methods now need to be developed for predicting traffic and evaluating the returns. The key parameter used is time, which places a figure on the generalized profit of a given trip.
But time has as many values as there are clientele segments. The value of time has no meaning. Distinctions must be made between the ideas used (guardianship value, revealed values, households’ and companies’ willingness to pay) in as fine and realistic a marketing framework as possible. The values obtained also depend on the mathematical models used to stimulate the use of the infrastructure.
These distinctions explain why published time evaluations vary so widely. The whole game of transport “marketing” revolves around treating the user as an individual customer exercising freedom of choice, rather than as the captive of a given mode of transport.