A World Health Organisation study in Austria, France and Switzerland suggested that the extremely small particulates (PM10s) emitted in car exhausts killed more people than road accidents. The study stated that they were responsible for 21,000 deaths, 300,000 cases of child bronchitis and 395,000 cases of adult asthma every year. The cost of all this is 1.7% of the three countries’ combined gross domestic product (GDP).

If the full cost of motoring to the NHS were taken into account, higher spending on public transport and laws to reduce driving would be more publicly acceptable.