Back to Visual-tm home On to Visual-tm and ERICA5 ERICA5 is software which builds origin-destination trip matrices from origin-destination (o-d) trip record data, statistically merging it, using DfTs variance weighting methodology. This takes account of double counting, multiple screenline crossings and the problems associated with motorways. The o-d data can include data from roadside, household, on-train or on-bus interviews and pre-existing matrices.
ERICA5 has been developed during a series of important research projects for DfT into matrix building. Initially developed for the ERTM/ SERTM models to hold the extensive London rsi’s, it was used to statistically build consistent trip matrices by merging the origin-destination movements using DfT’s variance weighting taking account of trips, which wiggle across rsi screenlines and the problems associated with motorways. It was extended during the MYSTIC project to hold household data as well as pre-existing matrix data. The merging was extended to allow inconsistent zone specifications and matrices were built from UK datasets in the Southeast, West Midlands, Manchester and Scotland to give National coverage as well as international datasets from the UK, France, Germany, Norway, Sweden, Denmark, Finland and the Netherlands. It was extended on the DATELINE project to build long-distance matrices for the whole of Europe; on the West Midlands PRISM model to cover inferring and on Cheshire County Model to cover merging datasets with different zone systems.
ERICA has been used since 1992 to build matrices for most of the models around London including: ERTM/SERTM, MUM, LASER, NAOMI, LATS, County models in Surrey, Kent and Hertfordshire and various scheme appraisal models. Special versions of ERICA have been developed and are being used in the Census Matrix Tools software, for the DfT’s rail passenger matrix builder, for the European MYSTIC matrices and for the DATELINE long-distance household travel diary database and modelling.
ERICA5 is usually supplied within a special version of Visual-tm (Visual-tm Erica edition or Visual-tm Corporate edition). ERICA5 is the matrix builder and our Visual-tm software is its front-end which provides a user friendly interface for the ERICA5 control files as well as essential functions for cleaning the raw data, coding postcodes to geo-codes and geo-codes to zones, expanding roadside interview data to classified counts, tabulating and analysing the o-d database.
Visual-tm ERICA edition is available for PC’s running 95/2000/XP servers or above. For further information please contact us. ERICA is owned by DfT and contains Peter Davidson’s fast low-level object library for handling very large datasets and very large matrices.
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