STRUCTURING CATEGORY ANALYSIS USING STATISTICAL TECHNIQUE

The transportation-planning process incorporates the development of re presentative-trip-generation models from base year data for making for ecasts of travel in subsequent years. Category analysis is a technique based on the unit of the household and its characteristics. The data are cross-classified over various socioeconomic schemes. Trip rates ba sed on such schemes are made for a particular category of analysis uni t. When the household characteristics are cross-classified with the av ailable data, certain cross-classification cells may get sparse data a nd certain others may not get any data. Under such circumstances, conv entional application of category analysis may not be appropriate. To o vercome this difficulty a linear statistical model framework was devel oped. The estimated mean trip rates for the cells of the cross-classif ied table use a model fit based on data from all cells and not just th e data from any given cell, which may not be reliable. Developed model s were illustrated for the different cross-classification schemes.