The estimation of origin-destination matrices by constrained generalised least squares Export

@article{bell-1991, abstract = {The Generalised Least Squares (GLS) approach to the estimation of Origin-Destination (OD) matrices permits the combination of survey and traffic count data in a way that allows for the relative accuracy of the two data sources. However, the procedure may result in estimates that infringe non-negativity or other constraints on the fitted values. A simple algorithm to solve the GLS problem subject to inequality constraints is presented and its convergence is proven. Expressions are derived for the variances and covariances of the fitted values both without active constraints. It is demonstrated that the imposition of inequality constraints can improve the accuracy of those fitted values directly and indirectly affected them, by reducing their sensitivity to error in the inputs.}, author = {Bell, M.}, citeulike-article-id = {6037539}, issn = {01912615}, journal = {Transportation Research Part B: Methodological}, keywords = {gls, matrix, od}, month = {February}, number = {1}, pages = {13--22}, posted-at = {2009-10-29 22:00:45}, priority = {0}, title = {The estimation of origin-destination matrices by constrained generalised least squares}, volume = {25}, year = {1991} }

TY - JOUR ID - bell-1991 L3 - citeulike-article-id:6037539 N2 - The Generalised Least Squares (GLS) approach to the estimation of Origin-Destination (OD) matrices permits the combination of survey and traffic count data in a way that allows for the relative accuracy of the two data sources. However, the procedure may result in estimates that infringe non-negativity or other constraints on the fitted values. A simple algorithm to solve the GLS problem subject to inequality constraints is presented and its convergence is proven. Expressions are derived for the variances and covariances of the fitted values both without active constraints. It is demonstrated that the imposition of inequality constraints can improve the accuracy of those fitted values directly and indirectly affected them, by reducing their sensitivity to error in the inputs. IS - 1 JF - Transportation Research Part B: Methodological SN - 01912615 EP - 22 TI - The estimation of origin-destination matrices by constrained generalised least squares VL - 25 SP - 13 KW - gls KW - matrix KW - od AU - Bell, M PY - 1991/02// ER -