Progressive transmission represents an effective means for the transmission of spatial data over the web. We classify current implementations of this paradigm as either view- or scale-based, which transmit data in a manner which is a function of the required map region or scale respectively. Although many such approaches exist, the concept of one which is both view- and scale-based has received little attention. This can be attributed to the difficulty in maintaining topological equivalence between the transmitted and original map. In this paper we propose a novel methodology for progressive transmission which overcomes this difficulty. Results demonstrate that significant reductions in the amount of data transmitted are achieved when compared to view- and scale-based approaches.