From single to double track: effects of alternative extension measures

Abstract

The growth of railroad line demand in Sweden is causing the industry to evaluate how to provide additional railroad capacity. One answer is to extend single track railroad lines into double track lines. This paper discusses three small measures that can be implemented on single track lines prior to extending them completely into double track lines. These are: (1) extending crossing loops to allow for parallel entrance, (2) providing additional crossing loops, and (3) implementing partial double tracks. The impacts of these three measures are evaluated. The results of the evaluation indicate that none of these measures will provide sufficient additional capacity. However, all three of the proposed measures lead to higher timetable flexibility, which can also be a benefit.