In many advanced economies, car use per head, and sometimes total car traffic, has shown low growth. In some countries (and especially cities) it has declined. In a few countries, there have been similar studies of the distance travelled by all modes added together, which has shown a similar trend though with some doubts about how international air travel should be handled. It is generally agreed that the trends in the last few years must be influenced by world economic problems, but some of the possible changes in trend seem to go back ten or twenty years, with signs detectable even longer…