Establishment of Taxi Driving Conditions and Emission Inventory in Tangshan City

The project team selected 3 taxis in the built-up area of Tangshan City to conduct emission tests under actual road conditions, systematically and comprehensively evaluated, analyzed and compared the test results. They established the VSPbin emission rate database and emission factor list of typical urban Taxis in the built-up area based on the actual driving characteristics of Tangshan city. To analyze the driving conditions of taxis in Tangshan City, this study selected four operating conditions: acceleration, constant speed, deceleration, and idle. The research results showed that as the emission standards became increasingly strict, the emission of single-vehicle pollutants decreased, and in particular NOx emissions were reduced by more than 90%. Compared with gasoline fuel, CNG fuel taxis’ CO2 and NOx emissions showed a downward trend. When natural gas was used as fuel, the CO emissions of taxis could be reduced by 27.2% ∼ 92.0%, and the CO2 emissions by 19. 5% ∼ 32.1%. The CO and CO2 emission factors of taxis both decrease with the increase of speed. For particulate matter, the quantity and quality emission factors both decrease first and then increase with the increase of speed, and the rising speed is obviously accelerated during the high-speed phase.