PRISM 2011 Base

PRISM West Midlands is a travel demand model forecasting system which was developed by RAND Europe and Mott MacDonald on behalf of the seven metropolitan districts in the West Midlands Metropolitan Area, the Highways Agency and Centro. The model system is required to be responsive to a wide range of policy levers, and to assess the impact of different policies on specific segments of the population. The original model development was undertaken between 2002 and 2004, with a base year of 2001, and a number of enhancements have been made to the model system since 2004, including adding incomes to the model, and an improved treatment of cost sensitivity and updating the base year to 2006.

In the PRISM Refresh project, the demand and network models in PRISM have been more fundamentally updated to reflect a 2011 base year. RAND Europe's role was to re-estimate the demand models using household interview data collected between 2009 and 2012, and deliver to Mott MacDonald an operational demand model implementation that can run together with the network models in the overall PRISM model system. The work was again undertaken on behalf of the seven metropolitan districts in the West Midlands Metropolitan Area, the Highways Agency and Centro.

This report documents the development of the updated travel frequency and car ownership models. Frequency models have been developed for 14 travel purposes. Travel frequency is predicted by applying two linked sub-models to predict the total amount of travel an individual makes on an average weekday in school term time. The first sub-model predicts whether an individual makes any travel, the second sub-model predicts how much travel will be made given that an individual makes at least some travel.