Abstract. Using Portable Emission Measurement System (PEMS in short), the PM and gaseous pollutants emission in China Ⅲ light-duty diesel vehicle before and after installing DOC+POC under cold and hot start conditions are studied respectively. Meanwhile, the POC filtration efficiency and size distribution of both particle number concentration and mass concentration are analyzed. The result show the PM emission from vehicle installed POC can meet China Ⅳ standard, and the filtration efficiency of both particle number and mass is 25%~55% under cold and hot start. POC filtration efficiency under cold start is 10% higher than hot start. However, the filtration efficiency is different under different size distribution. PM is generated mainly in acceleration process.

In 2012, for the first time China implemented the toll free expressway policy for part of vehicles on major holidays. However, there is no universal compensation mechanism thereafter. How to choose the compensation basis is the core issue of establishing such a mechanism. A proper solution is to choose suitable data of listed expressway companies as the basis. Factors including corporate social responsibility and compensation theory being taken into account, listed companies with an over 95% ratio of toll operations are sifted out, and part of companies with low efficiency are wiped out by DEA Models. 5 listed companies stand out from data sieving on Annual Reports 2012. Data can serve as the compensation basis of the year.

Based on the research of the traffic flow model, generating the Vehicle Hours Travelled (VHT) and weight factors matrix of different cities in different speed phase by using the GIS whole road network data and traffic low-frequency dynamic data. Applying weighting factors to generate a unified speed - acceleration distribution of different cities in different speed phase with chi-square test to select candidate short trips, and to determine the test cycle duration of each phase in developing Chinese Light Duty Driving Test Cycle.

Plug-in hybrid electric vehicles (PHEVs) have been greatly promoted due to their advantage in both vehicle performance and energy conversion efficiency. However, real-world emission measurements are rarely conducted for PHEV under different initial battery state-of-charge (SoC). In this study, a portable emission measurement system (PEMS) was employed to investigate the real-world emissions of carbon monoxide (CO), nitrogen oxides (NOx), and carbon dioxide (CO2) from a Euro V PHEV under fully and uncharged initial battery SoC. Compared to the emissions under the uncharged state, the average emission factors (EFs) of CO, NOx, and CO2 under the fully charged state are reduced by 72.2%, 27.8%, and 29.0%, respectively. And the reduction effect on the urban road is much more significantly prominent compared to that on the rural road and highway. In addition, obvious reduction effectiveness can be found for CO EFs in different average speed bins, especially those with speeds above 100 km/h. For NOx and CO2, however, the average speed-bin EFs are reduced only when the speed is below 70 km/h, while no obvious differences can be found when the speed is above 70 km/h. Furthermore, for the average vehicle specific power (VSP)-bin emission rates, obvious reduction effectiveness is observed for CO in different speed ranges, and for NOx and CO2 in the low- and medium-speed ranges except the high-speed range.