Abstract： To clarify the importance of urban road vehicle driving cycles as nonstandard driving cycles in vehicle emission assessment, the localization characteristics of urban road vehicle driving cycles were analyzed from the time and space dimensions. By collecting the actual onroad driving data in Nanjing city, the microtrips were extracted from timespeed data using principal component analysis and cluster analysis to construct the Nanjing local driving cycles, and the Nanjing local driving cycles in 2017 and 2009 were compared and analyzed from the time dimension. The Nanjing local driving cycles in 2017 were also compared with the local driving cycles in other cities in China, and the localization characteristics of urban road vehicle driving cycles were analyzed from the spatial dimension. The results show that even the same test and data processing methods are used in the construction process of local driving cycles, there are still significant differences for Nanjing local driving cycles in different years. Due to the significant differences in driving parameters among domestic cities, it is necessary to construct the local driving cycles in different cities. The local driving cycles should be constructed and updated regularly, which is helpful to obtain consistent emission factors with the actual emissions of inuse vehicles.
