Climate change and global warming is challenging task ahead. This text book covers the fundamentals of estimating emission factor with special emphasis on motorcycle exhaust emissions. For the first time the text integrates various modelling techniques found in literature and their respective application for predicting emission estimation. The book is unique in that it presents the application of Driving Cycle, and use of Onboard Emission Measurement, Chassis dynamometer methods for estimating/predicting the vehicular pollutants in building accurate atmospheric emission inventory. It provides a step-by-step approach to develop driving cycle with many examples of Edinburgh and discussions. The main topics covered include fundamentals of driving cycles,methodology and limitations of various modelling techniques.It incorporates various components of driving cycle and estimation of motorcycle emission.This book provides a platform for a large number of potential future applications for the evaluation of emissions and policy of air pollution reduction. Researchers and graduate students would find this book an indispensable resource.