Abstract
The consumption of petrol by cars increases as the speed is higher, so speed limits will give the possibility to decrease the fuel consumption. Calculations are made to estimate the decrease of fuel consumptions by speed limits of 100, 90 and 80 km/h for traffic outside built-up areas. It is concluded that in spite of the rather small accuracy of the calculated savings even the optimum of attainable reduction by speed limits is only a small percentage.