This study aims at developing a model system to examine the changes in the car market configuration, the life cycle CO2 emission from automobile transport and the tax revenues due to different taxation policies. The model system specifically determines the effect of varying the weights of the tax components in the stages of a) car purchasing, b) car owning, and c) car using to the changes in the car class and age mix and the car users' driving pattern and behavior towards car class choice and decommissioning. Five sub-models comprise the model system, formulated using car ownership related data in Japan from 1980 to 1994. Performance tests conducted against the sub-models generally yielded encouraging results. The sensitivity analysis identified car usage tax as the most significant parameters in reducing CO2. An increase in, ownership tax, on the other hand, significantly results in a shift to smaller cars, while the propensity to decommission and repurchase can be reduced by increasing the purchase tax and can be decreased by increasing the ownership tax. The model system was utilized to determine the impact of the 1989 tax reform and to forecast future scenarios using different taxation schemes. The model system is being further developed for possible future application in other countries.
