Last Updated:
22 May 2019

PPIAF Traffic Risk Brief: Delusion, Distortion, and Curses: Bias in Traffic Forecasting

This brief is part of a series that summarizes the content of the PPIAF-funded guide, Toll Road PPPs: Identifying, Mitigating and Managing Traffic Risk.

Low traffic volume, and the low toll revenues that result, contribute greatly to the failure of toll road public-private partnerships (PPPs). The risk has several sources, including forecasting error, uncertainty inherent to the forecasting process and bias.