Transport policy is, and has always been, largely focussed on enabling further, faster, cheaper and ever-more seamless travel, whether for journeys by individuals or for the carriage of freight. In the area of planning the focus has been more on geographical spread; lower residential densities; and public, commercial and industrial facilities sited in locations only conveniently reached by car and lorry. This has resulted in increasingly numerous journeys to more distant destinations made accessible by high-speed, energy-intensive road and rail transport or by flying. This has led to a considerable growth in traffic mileage and the accumulation of greenhouse gases in the atmosphere. My work examines the relationship between urban land use and transport policy; the role of public transport; the wide-ranging consequences of the rise in the ownership, use and dependence on cars and the increases in distances travelled by air.

I have paid particular attention to problematic assumptions underpinning policy of the past few decades. These are reflected in the calls for ever-more investment in and subsidy for road, rail and air transport to meet a seemingly never-ending growth in demand. However, to limit the most severe impacts of climate change, an urgent and comprehensive reappraisal of transport and planning policy is required to achieve a massive and speedy decline in this pattern of behaviour.

Another important strand of my work, much of it in collaboration with Stephen Plowden, has focused on road safety. We have concluded that a radical appraisal is needed of the methodology employed used to determine and enforce speed limits. This should cover the consequences beyond those relating to road injury and, in particular, include environmental and social effects. I have repeatedly argued that measuring road safety solely in terms of casualties is inadequate because it ignores other indicators, such as the perception of a greater risk of injury from more and faster-moving motorised traffic. This discourages people from cycling and also contributes to parental decisions to deny their children the freedom to get about on their own outside the home.