| Abstract: | In The Netherlands, tunnels are in much (public) demand since approximately 1980. Infrastructure is less tolerated in the urban environment, especially when it is elevated above ground. Three different projects for which the authors acted as scientific consultants can serve to demonstrate how problematic it can be to neglect an underground option on the one hand and to make it dogmatic on the other. Existing infrastructure is often seen as both environmentally and commercially damaging, suppressing urban land values. Reconstruction is a difficult task, though, in spite of modern techniques. The Helmond case, where an elevated part of a main road separates the town centre and historical castle and blocks revitalisation of the area, is an adequate demonstration. The proposed replacement with a tunnel proved to be ill considered, i.e. both difficult and costly. Even worse: perhaps the town might do without the road after all! In developing new infrastructure, like high speed train links, urban alignments are avoided because of public resistance. Yet these may prove to be acceptable if tunnelled, whereas an alignment in the rare open countryside is locally despised. This proved to be true in the case of the Amsterdam–Antwerp High-Speed Railway Line (HSL), for the passage of Dordrecht, south of Rotterdam. An urban underground solution was not considered in the government studies. A local proposal, which proved to be quite feasible, was rejected, mainly because it was presented late in the planning process. New types of infrastructure may be developed explicitly for underground use. Lorries are an ever-bigger problem in local distribution, both for the environment and congestion and for trade, dependent on these. Therefore, underground logistic systems (ULS) are proposed more frequently. Perhaps the best-studied one is the Schiphol Airport ULS, intended predominantly to connect air and rail terminals and the world's largest flower auction at Aalsmeer. It showed that the choice for an underground solution can be too dogmatic, not affordable and only partly necessary. Mixed solutions, partly underground, partly on the surface and partly elevated were quite feasible and economically more attractive. |
