Use of retail services. In Section 5.2.5 we showed how the demand for retail services is generated from both homes and workplaces and we also showed how the model could be disaggregated. Introducing a slightly new but obvious notation to deal with the two separate origins of service sector trips, we can write the model as
where A~g Ag spgl/LW.e-Cij
1 j J and
together wi th
(6.62) The superscript p now distinguishes origin of trip, with p = 1 representing home and p = 2, work. This formalism also has the advantage that with suitable definitions of g it could be extended to include the demands on service sectors by other sectors (over and above the demands of their employees). P.