Modal Split Changes Introduced by the High Speed Line Madrid-Seville
MENENDEZ J M and GUIRAO B, ETSI Caminos, Universidad Politecnica de Madrid, Spain
Investment in infrastructures always constitutes an important item in the Public Budgets of a country, a regional or a municipal government for that matter. They are, in short, that share of the public expense any government would generally pursue to make
Investment in infrastructures always constitutes an important item in the Public Budgets of a country, a regional or a municipal government for that matter. They are, in short, that share of the public expense any government would generally pursue to make profitable either on account of a social and/or a financial benefit. The optimal traffic volume necessary to achieve a return on any given infrastructure should be bounded by a maximum limit so as to prevent congestion, and by a minimum restriction so as costs from construction and refurbishment be justified. This is why an accurate assessment of the prospective traffic flow in a new infrastructure turns out an invaluable tool in the hands of developers and decision -makers.
The phenomenon of the induced traffic came to a head as a result of the serious congestion problems experienced in several roads in the UK, more particularly, in one of the most important orbital motorways of London, namely, the M-25. Thus, the enormous gap opening between actual and forecast flows became a major concern for researchers in this field. The trend of the demand in the London case could not only be attributed to the natural progressive growth of traffic rates in the city; moreover, there was not solid evidence supporting the idea that miscalculations in the appraisal could be liable for so exorbitant an increase.
For more than one decade, experts in the UK have often associated induction with an unexpected growth in roads. Owing to this fact, most of the literature on the subject is based on construction and upgrading projects undertaken in the said country. In fact, the first fully structured report on the phenomenon of induced traffic is the British Trunk Roads and the Generation of Traffic (SACTRA, 1994). However, England is not an isolated case regarding this experience. Other examples are the Amsterdam Ring Road in Holland, the tunnel highway stretch of Austria (Arlberg Tunnel), and the M-40 orbital road in Spain.
As a result of both the implementation of new high-speed lines in Europe and the transfer of passengers from other modes, the induction phenomenon has come to be associated once again with another mode of transportation, in this case, the rail mode. To illustrate the trend, we can mention, as an example, the new Paris-Lyon railway and also the rest of European high-speed lines. At present, Spain is living through a key period as regards the expansion of its national high=speed rail network. Following the opening of the stretch Madrid- Seville in 1992, the new line Madrid-Barcelona will come into operation by 2004. At the same time, there are projects for the relations Madrid-Valencia, and Madrid-Valladolid.
The absence of a unique definition for induced traffic -a global definition to be applied to all transport infrastructures- coupled with the impossibility to avail of a definite analytical approach for its quantification have boosted the making of this research work.
Association for European Transport