 Perhaps you should draw your article to the attention of the transport minister, Philip Hammond (Cut your speed, cut your petrol bill, 12 March). He is pressing for an increase in the motorway speed limit at the same time as his colleagues in the Department of Energy and Climate Change are looking to reduce the country's oil consumption in the face of fluctuations in oil prices, in addition to climate change pressures.  Martin Quick  Stroud, Gloucestershire