This study compares the environmental impacts of urban public transport and automobiles (energy use, emissions, noise nuisance, waste materials and use of space). For this purpose two models have been developed FACTS-Urban (Forecasting air pollution by car traffic simulation) and MILOV (environmental impacts of PT). Current Dutch situation as well as future scenarios on the demand side and the (technological) supply side have been studied. Generally speaking PT (especially rail) is and will remain cleaner than the use of the car. However, the environmental advantage of Diesel buses over passenger cars is diminishing rapidly.