Travel is central to our lives: for our daily commute, getting children to school, shopping trips, social activities, holidays and the rest. For individuals, how we travel changes through our lives, becoming more varied as we reach adulthood, when we may learn to drive and as incomes increase. Decisions about where we live and work are important for how we travel. To understand how the aggregation of decisions by individuals leads to the observed behaviour of populations, our main sources are surveys of travel behaviour, of which the most important are those carried out by national governments.

The British Department for Transport first commissioned a National Travel Survey (NTS) in 1965. The survey became a regular event starting in the early 1970s, and is now carried out annually, involving 16,000 representative individuals (a different sample each year) completing travel diaries with full details of their movements for seven days. These have provided time series of travel data spanning 45 years in considerable detail. The NTS covers all modes of travel except international air, so in effect it largely records the pattern of our daily travel, the trips that take us away from home each day.

The United States Department of Transportation carries out its National Household Travel Survey less frequently. This started in 1969 and takes place at intervals of five to eight years, most recently in 2017 when 130,000 households participated, individuals logging travel for one day of the week only. Other countries that conduct national surveys include Germany, the Netherlands, Sweden, Denmark, New Zealand and South Africa. Such surveys allow us to understand how the transport system is used, as well as how uses change over time – the topic of the next chapter.

The broad picture we find for Britain is that in 2017 (the latest available data), on average people made 975 journeys a year, travelling 6,580 miles, spending 377 hours a year on the move, which is close to an hour a day. These are averages for the whole population, so we expect quite wide variations to be found among individuals. Some people rarely leave home, for instance due to disability, while others commute heroic distances.