This paper compares and contrasts studies car`ied out by Travers Morgan involving the assessment of two national transport proposals in London - one the major improvement of the South Circular Trunk Road, the other the introduction of a new high speed rail link between Paddington and Heathrow. In both cases, it was argued that tunnelling, where practicable was the best environmental solution in the long term, even though it was more expensive and likely to cause significant construction disturbance in the short run. Initially, and largely on cost grounds, the high speed rail link had been proposed by the British Airways Authority/British Rail consortium to run on embankment and viaduct over the length of the new construction was envisaged. The possibility of on-line widening at grade, to the South Circular was also considered, but this was not favoured on environmental grounds. During the ensuing discussion, through a formal public consultation exercise in the case of the road proposal and a House of Lords Select Committee hearing in the case of the rail proposal, it became clear that there are mixed feelings towards tunnelling as an acceptable answer to reducing environmental impact of infrastructure developments in urban areas. While the initial rail proposals were modified to accommodate a tunnelling alternative, the road tunnels did not attract universal acceptance and simpler, at-grade options were put forward. The paper points to the seemingly inconsistent approach in weighing important proposals from the environmental point of view. It concludes by pointing to the need for a clearer understanding of the short term and long term implications of national transport projects, particularly with regard to the balancing of local and national interests.
Abstract