Estimating an O-D trip matrix from traffic counts has been very attractive mainly because of its inexpensive property. This paper reviews the range of mathematical models which have been applied in this area and draws attention to the main analytical difficulties. The development of a macro named ME2CON is described, which has been developed to estimate an O-D trip matrix from traffic counts on a congested road network. This macro applies the maximum-entropy matrix estimation (ME2) model and uses equilibrium assignment in conjunction with EMME/2, a well-known transportation planning package. A successful implementation of the macro ME2CON on an hypothetical road network and assumed traffic counts is reported, although convergence cannot be guaranteed under all conditions due to the under-specified mathematical problem which the ME2 model attempts to solve. (A)
Samenvatting