Samenvatting
Recent vehicle speed surveys provide greater detail and accuracy than previously, and suggest a dramatic increase in excessive speeds on UK roads. As vehicles travel faster, the energy required to overcome aerodynamic drag increases approximately exponentially, and becomes the dominant term in total fuel use. The ERR Transport Emissions Model was used to calculate the additional energy consumed, and the potential savings from enforcing or reducing speed limits. The results suggest that 3.1% of car CO2 emissions (0.6 Mt C) could be saved if current speed limits were enforced, or 7% (1.4 Mt C) if a maximum limit of 50 mph were imposed. (A)