This study was carried out at the request of the United Nations Centre for Human Settlements (Habitat). The primary aim was to review the market, organizational, and regulatory characteristics of the informal transport sector throughout the world with an eye toward identifying promising enabling and remedial strategies. The hope also was to give greater visibility to this often ignored sector. Brian Williams was Habitat's project officer in charge of overseeing the work. I owe a great deal of gratitude to Brian for helping conceptualize the study and define the research approach, and for providing helpful suggestions throughout.