In 1999 we estimated the revenue forecast for a short toll tunnel road leading into downtown Bilbao for Dragados y Constructiones, in preparation for their bidding to build and operate this new toll road. Our estimates came within 95% of the actual volume. We used a logit model calibrated based on revealed preferences from a nearby toll road. Our demand model was used only to obtain the LOS for toll and non toll roads, thus applying the logit model outside the assignment phase.
Unfortunately, the Provincial Government had to rescue the concession in 2010 as the bidding winner relied on faulty estimates by other consultants claiming twice the actual revenues. Apparently the analytical approach relied on a simple static assignment assuming a simple value of time to describe the time penalty associated to the toll
In 2008, we concluded a revenue forecast for BIDEGI, agency managing the Gipuzkoa Province toll roads, as the existing toll road was expanded thanks to a new bypass around its capital, Donostia-San Sebastian, plus the completion of the toll road extension towards Vitoria-Gasteiz in the southwest.
The approach was based on a logit-path approach built into the assignment phase, considering several user typed for light vehicles based on trip purpose and eligibility to toll discounts either through frequent usage or place of residence. Similarly two heavy vehicles user types were considered based on total length and weigth. The estimates for the mid and long term future were calculated using Scenario Planning given the many uncertainties associated to demographics, oil prices, economic development and potential European policies on Climate Change.
As on this date, and in spite of the current economic recession, total revenues are within 95% of the forecast values.