This document gives guidance on the analysis of forecasting and uncertainty in transport appraisals.
In November 2014, Section 8.3 of this unit was updated upon a department review of PDFH 5.1. This section now reflects recommendations adopted into WebTAG. An updated example in box 3 of using NTEM growth for fixed demand models is provided.
The previous version of this unit was TAG unit M4 forecasting and uncertainty, May 2014.
WebTAG provides information on the role of transport modelling and appraisal, and how the transport appraisal process supports the development of investment decisions and business cases.