摘要：Object conflicts—struggles over the design, definition, and diffusion of technologies—are analyzed to understand the changing history of the greening of bus technologies in the United States from the late 1980s to 2006. Conflicts are examined over the controversy between compressed natural gas (CNG) and emissions-controlled diesel (ECD) buses in four fields: regulations, research on emissions differences, fleet-purchase decisions, and political mobilizations from bus users and environmental justice groups. Given rapidly changing scientific research on emissions and health effects and rapidly changing bus technology, controversies tend not to stabilize or close for long. In general, the trend has been for some of the largest city bus fleets to reverse pro-CNG decisions in favor of ECD. A framework for the analysis of “object conflicts” is developed to elucidate the factors behind the choices between ECD and CNG and to provide a general model for thinking about technology politics and sustainability.
关键词：motor vehicles;urban environments;technology policy;risk factors;emission measurement;decisions;social action;public health
