Exhaust emission and fuel consumption of a vehicle is influenced by its usage, operating conditions, traffic conditions as well as the individual behaviour of the driver. A study on the actual operating conditions for city buses has been carried out for Delhi city under a Government sponsored Project by The Automotive Research Association of India (ARAI).A bus operating on the normal city route was selected and equipped with sensors and data acquisition systems to record the vehicle parameters such as vehicle speed, distance, time, gear shifting pattern, engine speed, temperatures and other variables every second. The data collection exercise was carried out on six selected routes covering lean, average and peak periods of traffic and vehicle density. Earlier experience shows that data thus collected can be synthesised to fall into statistical repetitive driving sequences. This averaged data is converted into a most logical driving pattern or cycle for buses operating in Delhi city.The paper describes the data collection exercise, the analysis of said data and derivation of the driving cycle from thereon. The driving cycle data thus generated could be coupled with driving patterns from other metropolitan cities in India, which would give a final representative driving cycle for buses in Indian cities. The driving cycle thus derived would be useful as a Standard reference Driving Cycle for Buses for carrying out developmental work by the manufacturers, Institutions, academicians and Regulatory Bodies to work on the influences of various design options of the product and obtain optimum solution for performance, fuel economy, emission with alternatives of design parameters and control strategies.