Traffic organization design plays a decisive role in the micro-operation of transportation. Taking one-way traffic organization as an example, in order to reveal the characteristics of traffic operation and its impact on vehicle emissions, this paper constructed a measurement method to divide vehicle emissions into two sections: vehicle operating on roads and at intersections. The emissions from each section were calculated by determining the emission factor and emission rate. Vehicle detour was considered and the calculation method of detour-related emissions was proposed. Using Tangyan Road-Fenghui South Road corridor in Xi'an, as the study case, the results showed that the unit turnover emissions of CO2 and CO, HC, NOx on roads after one-way traffic were 503.76 and 1.91, 0.27, 1.07g/vehicle/km, which decreased by 5.6%-12.4% compared with that before. At intersections, the emissions of CO2 and CO, HC, NOx decreased by 23.8% and 27.5%, 25.3%, 19.4% respectively. Regional total emissions decreased by 7.9%-20.5%, with an average decrease of 14.1%. The overall emission level of detour vehicles is still lower than before because one-way traffic has improved the traffic efficiency. This paper affirms the positive role of one-way traffic in restraining traffic disorders and reducing vehicle emissions, providing a basis for the comparison and selection of urban road management schemes to achieve low-carbon transportation.

One-way traffic;Before and after comparison;Emission factor