David Metz

The Myth of Travel Time Saving

Abstract The idea that the main benefit of improvements to transport infrastructure is the saving of travel time has been central to transport economic analysis. There is, however, little empirical evidence to support this proposition. Indeed, in the long run average travel time is conserved, implying that travellers take the benefit of improvements in the form of additional access to more distant destinations made possible by higher speeds. Such a perspective, based on considerations of the value of access, has implications for economic appraisal, modelling and policy.

Saturation of Demand for Daily Travel

Abstract Data from successive national travel surveys show that important characteristics of personal daily travel behaviour in Britain are comparatively stable. Over a 35‐year period, there has been little change in average travel time, journey frequency, purposes of journeys, and proportion of household income devoted to travel. The one factor that has changed significantly is distance travelled, as people have taken advantage of growing incomes to travel faster, thus gaining access to a greater choice of destinations. However, this growth in distance travelled has now ceased, an outcome which is helpful in relation to concerns about sustainability and the environmental impact of the transport system. The explanation proposed for this cessation of growth is that mobility‐based access and choice increase with the square of the speed of travel, whereas the value of additional choice is characterized by diminishing marginal utility. Hence, a saturation of the demand for daily travel is to be expected, a novel conclusion.

Peak Car and Beyond: The Fourth Era of Travel

There is emerging evidence that personal daily travel, particularly by car, has ceased to grow in the developed economies. This can be attributed to saturation of demand, given high levels of access and choice now widely available, together with constraints on higher speeds. We are therefore at a time of transition from an era of growth of per capita travel to an era of stability, in which the future factors determining the growth of total travel demand are demographic — population growth, increasing longevity, and urbanisation. The peak car phenomenon, which marks this transition, is seen in successful cities that attract a growing population whose travel needs are increasingly met by investment in rail-based transport, the revival of which is a characteristic of the new era.

Response to the Responses

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