DEVELOPING A TAIPEI MOTORCYCLE DRIVING CYCLE FOR EMISSIONS AND FUEL ECONOMY GWO-HSHIUNG TZENG and JUNE-JYE CHEN Energy and Environmental Research Group and Institute of Trac and Transportation, National Chiao Tung University, 4F, 114, Sec. 1, Chung Hsiao W. Rd., Taipei, 100, Taiwan (Received 14 November 1996; accepted 24 March 1997) AbstractÐThe purposes of this study are to develop a representative driving cycle for motorcycles in metro- politan Taipei and to ascertain the emissions and fuel economy of the cycle. We collected extensive driving cycle data and proposed a methodology to develop a Taipei motorcycle driving cycle (TMDC). The charac- teristics of TMDC are high average acceleration and deceleration, high acceleration±deceleration changes and low average travel speed. Forty-®ve motorcycles were tested in a laboratory by using the ECE-40 and TMDC test procedure. The emissions of motorcycles tested by TMDC are higher than ECE, whether they are two- stroke or four-stroke engines. Furthermore, the CO and HC emissions of two-stroke engine motorcycles are higher than four-stroke engine motorcycles, and the NOx emission of two-stroke engine motorcycles are lower than four-stroke engine motorcycles, whether they are tested by TMDC or ECE. The fuel economy of two- stroke engine motorcycles tested by TMDC is lower than ECE, but the fuel economy of four-stroke engine motorcycles tested by TMDC is higher than ECE. A linear regression of TMDC in terms of ECE emissions shows them to be highly correlated, as is fuel economy. # 1998 Elsevier Science Ltd. All rights reserved 1. INTRODUCTION The motorcycle is one of the most important transportation modes in the tropical±subtropical countries. In metropolitan Taipei, the number of motorcycles had already reached 1.95 million in 1995. The ownership rate is 0.33 units per person. Though motorcycles are convenient, the emis- sions of motorcycles are quite serious. According to the information from the Environmental Protection Administration, the HC and CO emissions of motorcycles occupy the ®rst and second places among all transportation modes. How to control motorcycle emissions is a major issue in improving air quality in metropolitan Taipei. The European driving cycle (ECE-40) has been employed as the motorcycle emissions test procedure (CNS 11386) since 1987 in Taiwan. ECE is one kind of steady-type driving cycle. However, it seems not quite suitable for the crowded trac of Taiwan so environmental protection authorities and research institutes are interested in how to develop a domestic motorcycle driving cycle and to discover the emissions and fuel economy of the domestic driving cycle. Therefore, the purposes of this study are to develop a representative motorcycle driving cycle in metropolitan Taipei and to ascertain the emissions and fuel economy of the cycle. We proposed a methodology, collected extensive motorcycle driving cycle data and developed a representative driving cycle. Then, we randomly sampled 45 motorcycles in use and tested the emissions of both the represen- tative cycle and ECE. Carbon balance method was used to calculate the fuel economy. We ®nd that the characteristics of the motorcycle driving cycle are high average acceleration and decel- eration, high acceleration±deceleration changes, and low average travel speed. The emissions tested by the Taipei motorcycle driving cycle (TMDC) are higher than ECE. The fuel economy of two- stroke engine motorcycles tested by TMDC is lower than ECE, but the fuel economy of four-stroke engine motorcycles tested by TMDC is higher than ECE. A linear regression of TMDC in terms of ECE emissions shows them to be highly correlated, as is fuel economy. We ®rst introduce the purposes and contents of this study. In the second section, we propose a methodology to develop a representative driving cycle. How to collect the driving cycle data in the metropolitan Taipei is described in the third section. Then, the characteristics of driving cycles in metropolitan Taipei are analyzed in the fourth section, and a representative driving cycle is devel- oped in the ®fth section. In the sixth section, the emissions and fuel economy tested by the repre- sentative driving cycle and ECE are analyzed. Finally, conclusions and recommendations are made. Transpn Res.-D, Vol. 3, No. 1, pp. 19±27, 1998 # 1998 Elsevier Science Ltd Pergamon All rights reserved. Printed in Great Britain PII: S1361-9209(97)00008-4 1361-9209/98 $19.00+0.00 19