Trends in suburban clustered employment growth (poly-centric development) occur large cities. Decentralized employment growth is complicated and subject to many factors. In fast growing cities of the developing world analysis is rarely undertaken when formulating master plans or spatial plans. An analytical framework of research aims, suitable techniques, and outcomes for policy analysis are described. Its practical utility to identify clusters and their dynamics is explored with available data for 1985 and 1997 for Istanbul. Impacts on commuting patterns (trip lengths, employment destination zonal preference functions and mode shares) are analyzed for each type of sub-center identified in Istanbul, and some findings contrasted with North American cities where such research into the dynamics of employment clusters has been undertaken. (C) 2007 Elsevier Ltd. All rights reserved.