Accepted: 5 February 2013 Frequent gridlocks and traffic jams during the periods of rush hours can result in long user delays and more vehicle emissions causing continuous degradation of air quality. The builtinfrastructure of densely populated cities and intercity travel by passenger and freight traffic lead to significant adverse impacts of traffic congestion on air quality, greenhouse gas emissions, and global warming. Transportation contributes 28% of energy related greenhouse gas emissions

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... in the U.S. This paper shows that traffic related carbon dioxide (CO 2 ) emissions are higher per capita for several rural and smaller cities compared to large urban areas in the United States. Inadequate use of mass transit, urban sprawl, construction of more roads and traditional stop-controlled intersections, and addition of more lanes to increase traffic capacity and ease congestion, are primary causes of significant vehicle emission inventory of CO 2 and air quality degradation. It is shown that sustainable traffic management policies, such as reduction of work-related travel by cars and more use of mass transit modes, can decrease CO 2 emissions. Case studies of value engineering applications are presented to select cost-effective less polluting mass transport strategies based on economic evaluation of life cycle costs and benefits.