Page 169 - 360.revista de Alta Velocidad - Nº 5

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número 5 - junio - 2018. Pág 167 - 189

KEYNOTE

Alternate Double–Single Track Proposals for Low and Intermediate
Demand High Speed and Conventional Lines

Castillo, Enrique

Grande, Zacarías

University of Cantabria
1

Abstract
The paper introduces the alternate double single track (ADST) as an alternative
to double track lines and discusses its main advantages and shortcomings. An
optimization program for the design of such lines are presented, including
a detailed analysis of the selected objective function and corresponding
constraints. In particular, some interesting formulas for deriving the upper
bound of the capacity of these lines are derived to illustrate how the efficiency
of the line can range from the single to the double track extremes. Some
possible international applications of this alternative are identified in which
the ADST could be advantageous. Finally, some real examples of applications,
which include the cases of Spain, Chile and Ireland, are used to illustrate the
proposed methods.

Keywords: Optimization, railway line design, rational investment analysis, Rail capacity, relative time

1 Castillo, Enrique. University of Cantabria. Email: castie@unican.es
Grande, Zacarías. University of Cantabria. Email: Zgandrade@gmail.com

International Congress on High-speed Rail: Technologies and Long Term Impacts - Ciudad Real (Spain) - 25th anniversary Madrid-Sevilla corridor 167