Transport is one of the largest sources of environmental pollution, and many of its impacts are increasing. Therefore, transport policy-making is increasingly being required to focus on issues of sustainability. The challenge is to identify the key issues and options for the medium and long term, and to make effective decisions now on initial actions in the face of much uncertainty. Scenario analysis is increasingly being used for such long-range policy formulation.
The main purpose of POSSUM was to develop scenarios showing how the objectives of sustainable mobility could be achieved in a European context, and to set out a methodology for this, centring on so-called Policy Paths comprising of packages of policy measures. In particular, the aim was to identify key issues for future decisions on the Common Transport Policy (CTP) and the Trans European Networks consistent with sustainable mobility.
Throughout this work, the project sought to establish the value of backcasting techniques for policy development. These involve working backwards from a desirable future end-state to determine a feasible means of achieving that outcome.
POSSUM illustrated that policy paths linking images of the future in 2020 up to the present day, are an effective means of establishing options for transport development in relation to developments in society.
Three Images were prepared, involving different combinations of technological innovation and decoupling of transport growth from economic growth. Using the ‘backcasting’ techniques, POSSUM provided a set of policy scenarios for the European transport system through to the year 2020 that could meet CTP objectives for economic efficiency, regional development and environmental protection. The scenarios explore alternative social and political developments outside the transport sector, and show what transport policies would then deliver the targeted outcomes. In particular, the relative roles of technology and reductions in the transport intensity of the economy are described.
The project identified a number of early policy actions that would be appropriate across all scenarios:
- Tax reform - a shift of the tax base from labour to the use of natural resources in order to strengthen incentives for dematerialization and energy conservation.
- Experiments with low emission zones - providing an incentive for the market to select clean vehicle technologies.
- Tele-commuting - experimenting with tele-working options in conjunction with land-use planning.
- Road pricing - taxation on the use of congested urban roads, coupled with measures that provide alternatives (such as quality public transport).
- Actions to provide integrated information systems.
Stakeholder consultations indicated that scenario building does generate innovative thinking on longer-term transport issues.
POSSUM characterised the CTP as facing large uncertainty with high potential impact. In this situation, the appropriate strategy is to proceed in small steps with frequent re-evaluations. It is also preferable to try several solutions in order to learn – the role of public policy is then to set targets that promote innovation and selection through market forces.
The main policy conclusions were:
- Both new technologies and the decoupling of transport growth from economic growth are needed to achieve sustainability targets.
- For technological innovation, action is needed at the European level to build consensus and provide incentives for rapid movement along clear technology trajectories. Support for innovation may need to precede open market developments.
- The CTP must be complemented by measures outside the transport sector (such as tax reform, regulation of information technology, and land-use planning).
- Those measures that have a long lead-time (e.g. aimed at changes in behaviour) must start early.
- Measures should be adapted to local conditions where uniform national or European policies would be inefficient.
- The Trans European Networks must form part of an integrated transport strategy, such that they do not simply encourage more travel overall.
- The growth in air travel and the increased demand for leisure activities (e.g. from an ageing population) will act as other major constraints on the achievement of sustainable mobility targets.