Patterns of usage of the road and transport system have changed considerably in the last 30 years. The concern for making the best use of available transport and road capacity expressed in the 1960s was to ensure that only appropriate journeys were made: the mechanism was road (congestion) pricing, and this theme was developed steadily over the next decade or more to include physical constraints on access to certain areas, capacity reductions, and a heightened awareness of environmental and social impacts. However, the rapid improvement of traffic management techniques, particularly area traffic control, led to significant increases in effective capacity, and the issue lay unacted upon. Recent developments in the fiscal analysis of toll roads have now begun to contribute anew to this debate, and the rising levels of urban and suburban congestion in several countries has led to tentative political backing for road (congestion) pricing, reaching the level of a formally-endorsed policy in the Netherlands. At the same time the major gains from traffic management innovations have begun to lose momentum, and the earlier solutions (including road congestion pricing) are becoming attractive and economic once again, with new technology making the technical aspects easier while raising more severe privacy and surveillance issues. The new technology is raising the level of capacity and safety by greater information and control for the driver and the vehicle. The difference now is that the changes in land use and activity locations, and the investments in public transport can no longer be treated separately. The management of travel demand must now be underpinned by methods of projection and proposal analysis that recognise these interactions in a reasonably quantitative manner and the information flows required to exercise this option also need attention. It is no longer possible to omit wider population, employment and environmental impacts arising from any of the three major players in the transport and land use system: the roads, the public transport and land use release and usage. More technology applied to the roadway and to the vehicle has a part to play, so too does land use release and regulation, public transport policies and expenditures and road provision. If travel demand is to be managed successfully, all three elements must be balanced with the social, fiscal and environmental costs and the responses of the users of each part of the total system. Work aimed solely at one part of this system is unlikely to be as successful (A).
Abstract