JOÃO BENTO is Professor of Design Support Systems in the Department of Civil Engineering and Architecture, Instituto Superior Técnico, Lisbon, and an executive member of the Board of Directors of Brisa, Auto-Estradas de Portugal, SA.JOSÉ P. DUARTE is Assistant Professor at the Instituto Superior Técnico, Lisbon.MANUEL V. HEITOR is Professor at the Instituto Superior Técnico, Lisbon, where he serves as director of the Center for Innovation, Technology and Policy Research. He is also a Senior Research Fellow of IC2 Institute, The University of Texas at Austin.WILLIAM J. MITCHELL is Professor of Architecture and Media Arts and Sciences, Head of Meda Arts and Sciences, and Dean of the School of Architecture and Planning, Massachusetts Institute of Technology.