Transport infrastructure, equipment and operations can have substantial environmental impacts. Noise, noxious emissions and visual intrusion can be a serious nuisance and lead to public opposition to new roads and other infrastructure. Carbon dioxide from transport sources also contributes to the build up of greenhouse gases. The Institution believes that we must make best use of the capacity of the existing transport network, and that additional capacity should only be provided in a manner which seeks to balance need, sustainability and affordability.
Reducing the need to travel
The freedom to travel and to transport goods is a vital characteristic of developed societies, but should only be exercised within constraints which recognise its social and environmental impacts. The planning system should be used wherever possible to reduce the need to travel and encourage more sustainable travel patterns. Priority should be given to mixed use developments in urban areas well served by public transport.
The concept of 'transport efficiency', analogous with energy efficiency, should be developed to break the conceptual link between transport growth and economic growth.
The differing needs of urban and rural areas must be recognised and any policy must have the flexibility to address both. Private car use is likely to remain the major option for many rural journeys and should not be unduly restricted where it does not contribute to traffic congestion.
The existing network
A rational pricing and financing regime should be established to reflect the social and environmental costs of different modes of travel. Over time, this will encourage more sustainable development and travel patterns. The impact of planning and pricing tools should be reinforced by encouraging use of modes which are comparatively less damaging to the environment, within an integrated transport network. Provision for convenient interchanges between modes and high quality current information are two essential components of such a network. For example, information on traffic conditions should encourage drivers to avoid congested areas.
Planning and pricing tools should be used to encourage use of more sustainable modes of freight transport, for example by provision of rail links to major freight generators.
The use of mitigating techniques such as noise barriers and landscaping to reduce intrusion and other environmental impacts of transport infrastrucutre should be developed and actively encouraged. Planned and timely maintenance is needed to avoid poor performance and early reconstruction.
Reducing road traffic congestion, if necessary through charging for road use and other penalties designed to discourage use of private vehicles in urban areas, should be a particularly high priority as it reduces emissions and increases the utility of the road network.
Improving provision of new resources
Solutions to transport problems must reflect social and economic objectives but should strive to achieve the best practical environmental option. For example, the land take and ecological disruption caused by an urban bypass should be weighed against emissions from urban congestion but also against other solutions such as traffic management measures.
Civil engineers must seek to improve the environmental peformance of transport infrastructure, for example by recreating landscapes and ecological habitats threatened by the development of new transport infrastructure.
Incentives should be provided to encourage transport of construction aggregates by more sustainable modes wherever possible. The use of rail and river transport, for the Manchester Airport Second Runway and the Jubilee Line Extension respectively, are commendable examples.
There is increasingly a need for new solutions to the demand for travel which minimise negative environmental impacts. These are likely to involve low emission and energy efficient vehicle technology. Further developments in emission control technologies and renewable or energy efficient fuels should be strongly encouraged.
When all these factors are taken into account, it will still be appropriate in some cases to provide additional transport capacity to meet demand. This should be recognised.