Multi-regional freight generation models
This study is concerned with the development of models for total and commodity freight by road and by rail originating from and terminating into the different regions of the U.K., as well as from and into 134 composite zones of these regions. Previous work is reviewed and improvements in freight generation modelling are sought in providing a conceptual framework, investigating a wider range of variables than hitherto and in tackling some statistical shortcomings in previous studies viz. the violation of assumptions that underly the use of ordinary least squares method and the effects of spatial and industrial aggregation. The main techniques used are regression analysis, principal component analysis and covariance analysis. The accessibility variables, however, are derived from the calibration of the group locational surplus maximizing model. The models are critically discussed and an attempt to relate the results to location theory is made. Subsequently the potential for future research and some planning implications are outlined.