The average household allocates 14 per cent of weekly spending to transport – which is also its largest single cost – while the foundation said the poorest households with a car were spending at least 17 per cent of their income on transport.
It said those in “transport poverty” far outweighed those in “fuel poverty” – people spending more than one tenth of their income on heating.
RAC Director Stephen Glaister said: “Rightly, there is much concern about the four million households who need to spend more than 10 per cent of their income to keep warm. Yet this figure is dwarfed by the 21 million (80%) households which spend over 10 per cent on transport. For the average household, transport is the single biggest outgoing, bar none. Just like heating our homes, most of us have to spend money on transport. There is no choice. While savings can be made at the margins by making fewer journeys and combining those which are essential, people have no option other than to go to work, visit the supermarket, see the doctor and take the children to school. That means paying for transport. It is true the cost of buying a car has fallen over recent years, but the cost of running one has soared. While most people can delay replacing their vehicle, they have to fill it with fuel, get it taxed and insured, and keep it maintained.