9-11 June 2004 In Britain, children are walking less than they used to. A major factor causing this decrease is the growth in car use. These trends are reducing children’s quantity of physical activity, with serious implications for their health. The purpose of this paper is to explore these themes using results from a 3-year research project entitled ‘Reducing children’s car use: the health and potential car dependency impacts’ which has been carried out in the Centre for Transport Studies at University College London in collaboration with others including Hertfordshire County Council, with fieldwork being carried out in Hertfordshire, an area immediately north of London. A major component of the project was a study of 200 children aged between 10 and 13 years of age using motion sensors coupled with the use of a travel and activity diary over four days. The sensors measured movement in three dimensions which was converted to activity calories, a measure of physical activity. Events from the travel and activity diaries were mapped onto the data from the sensors so that it was possible to isolate and analyse specific time periods, events and journeys. From these data, the comparative effects of different forms of transport on children’s physical activity have been established, producing clear evidence of the benefits of walking compared with car travel. It is found that the use of the car is linked to particular types of activity. For example, structured out-of-home activities, such as clubs and sports lessons tend to be reached by car while informal activities such as playing, are associated more with walking. This means that the shift from the latter to the former is one of the factors underlying children’s increasing use of the car. The motion sensors have facilitated the calculation of the intensity of various activities in terms of using activity calories. Walking is second only to physical education (PE) or games lessons in intensity. It was found that, for the older children, walking to and from school for a week used more activity calories than two hours of PE or games lessons, which is the recommended standard in Britain. It was also found that children who walk to activities are more active when they arrive at activities than those who travel by car, particularly in the more energetic activities, which suggests that walking brings wider health benefits than is generally recognised. Another strand of the project upon which this paper is based is the evaluation of walking buses. From the various surveys in the study it appears that about half of the trips on walking buses were previously walked, but there is not an equivalent decrease in the number of car trips because many of the children were being dropped at school in the course of a longer trip by a parent
