KABATA Traffic Consultant Has Average 118% Overestimation Error Rate for US Projects

March 9th, 2012

Terry Maynard, a retired federal economist working with a Virginia citizens group, has documented that KABATA traffic and toll consultant Wilbur Smith Associates (WSA) has overestimated toll revenue by an average of 118% for the first five years US toll facilities were open. A summary of the study appeared in Toll Road News.

Most of the data used in the analysis came from a study by the Transportation Research Board of the National Academy of Sciences. Maynard also used data from recent projects where WSA provided traffic and toll revenue projections.

A 118% average overestimation error is consistent with the 103% overestimating difference between the 17,700 vehicles a day in 2035 that CH2MHILL modeled from Scott Goldsmith of ISER’s demographic data for Anchorage’s Highway to Highway project. WSA projected 36,000 vehicles a day in 2035 and the revenue from that number is in KABATA’s financial plan.

The effect of overestimating Knik Arm Bridge toll revenue is discussed in Jamie Kenworthy’s revised Real Finances of the Knik Arm Bridge paper that projects a $2.5 Billion deficit under the current Public Private Partnership (P3) structure.

Perhaps aware of large bridge deficits under the P3 structure, last week at a 3/1/12 luncheon held by radio-host Dan Fagan, Anchorage Mayor Dan Sullivan endorsed a no toll bridge that the state would fully fund.