Development of a local real world driving cycle for motorcycles for emission factor measurements

The development of driving cycles is important for the success of a mobile source management program. A comparison between a localized driving cycle (Kaohsiung Driving Cycle, KHM), European (Economic Commission of Europe Driving Cycle, ECE), USA, Japanese and Hong Kong cycles was investigated in this study. The CO, THC, NOx and CO2 emission factors of the entire KHM and ECE cycles as well as the speed–time relationship between these two cycles were also compared in this study. Results indicated that the KHM and ECE as well as worldwide harmonized motorcycle emissions certification/test procedure (WMTC) cycles were completely different in driving characteristic parameters, emission factors and fuel consumption. For example, the time percentages of acceleration and deceleration of ECE cycle are much less than those values in Kaohsiung city. In contrast, the duration of cruising mode (8.6%) in the Kaohsiung area driving cycle is lower than those of ECE (32.3%), WMTC (27–53%) Japanese 10–15 mode (21.2%) and Hong Kong (9.4%). Results further indicated the emission factor ratios of the KHM and ECE driving cycles of 2stroke new/in-use motorcycles for CO, THC, NOx and CO2 were 2.5/1.5, 1.5/1.3, 2.0/1.4 and 1.0/1.0, respectively. In addition, the emission factors in the KHM cycle for 4-stoke cycles are higher than those of the ECE. For fuel consumption, the KHM cycle was 10% higher than ECE cycle for the same engine type. Consequently, the KHM pattern developed in the present study for the Kaohsiung metropolitan area should be used to truly represent the traffic pattern, emission factor and fuel consumption.