A SURVEY OF THE NUMBER OF COLD VEHICLES ON THE ROADS

The emissions from a petrol-driven private car with a cold engine are considerably greater than that of the same vehicle with a hot engine, regardless of whether or not a catalytic convertor is installed. For t his reason, the first part of the project has studied the proportion o f total emissions that are due to driving with a cold engine. When all private cars are equipped with catalytic convertors, the total emissi ons of CO and HC will decrease to similar to 43%, in comparison with t he situation in which no vehicles are equipped with catalytic converto rs. The distribution of the total emissions will be 60% and 40%, when driving with cold and hot engines, respectively. This is in spite of t he fact that petrol-driven private cars only drive with cold engines f or 9% of the time. In the future, one of our major tasks will be to re duce emissions resulting from driving with a cold engine. Thirty-four percent of all emissions results from journeys up to 6 km, with distri butions of 27 and 7% points for cold and hot engines, respectively, wh en all vehicles are fitted with catalytic convertors. In the effort to limit emissions, there is therefore clear potential for replanning sh ort journeys and using some other, less polluting, form of transport.