Strategic Environmental Assessment of Transport Infrastructure - the State of the Art
CHADWICK N, Steer Davies Gleave, UK
Whilst the global and national environmental effects of the development of the transport system have been well documented, Environment Impact Assessment (EIA) is typically only applied to individual transport infrastructure projects rather than wider poli
Whilst the global and national environmental effects of the development of the transport system have been well documented, Environment Impact Assessment (EIA) is typically only applied to individual transport infrastructure projects rather than wider policies, plans or programmes (often referred to as PPPs). As a consequence, the consideration of environmental effects is conducted at a local level. A number of limitations arising from this focus have been highlighted since the implementation of EC directive 85/337 (CEC, 1985) on EIA, namely:
* the consideration of alternatives in EIA is limited. This particularly relates to the consideration of different modes as means to serve identified transport needs.
* the consideration of cumulative effects of different elements of a transport infrastructure programme (or indeed the phased implementation of a single route) has proven to be difficult, particularly in relation to concurrent developments.
* the scope for effective mitigation is limited, particularly in terms of considering modal alternatives as mentioned above, but also in that key decisions on route alignments and project design have already been made before a project EIA typically is undertaken.
* EIA of individual projects is typically undertaken within a short timescale, which gives little scope to consider alternatives in appropriate depth.
* the opportunities for genuine consultation are limited because the scope of the project EIA is necessarily restricted, and key decisions on alignment and implementation have already been taken.
As well as addressing the limitations of project-level EIA, there are also other specific benefits of undertaking assessments at a strategic level, such as:
* the ability to assess individual components of a plan or programme on a consistent basis and to provide a means of setting priorities and phasing of implementation within the plan.
* the ability to adequately weigh issues of environmental sustainability at a level of policy-making appropriate to the scale of the problems being faced.
As a result of these concerns, there have been parallel moves in many countries towards developing an approach to the environmental assessment of policies, plans and programmes. In particular, the widespread nature of transport systems and their consequent environmental effects has meant that transport has been a sector where the potential benefits of Strategic Environmental Assessment (SEA) have been identified. A broad definition of SEA has been developed by Therivel et al (1992), namely SEA is:
"the formalised, systematic and comprehensive process of evaluating environmental impacts of a policy, plan or programme and its alternatives, including the preparation of a written report on the findings of that evaluation, and using the findings in publicly accountable decision-making".
This paper describes recent research work by Steer Davies Gleave (1996) which has assessed the current state-of-the-art of SEA for transport infrastructure with particular regard to recommending a methodology for application to the Trans European Transport Network.
Association for European Transport