3. Methods
3.1. Study area
The study area of this paper is metropolitan Perth, the state
capital of Western Australia and the fourth largest Australian city,
after Sydney, Melbourne and Brisbane. In Perth, there are
five train
lines (Armadale, Fremantle, Joondalup, Midland and Mandurah
lines), with one spur line (the Thornlie line), giving an overall
starlike shape to this system (see Fig. 2). The total railway is
173.1 km in length and covers 69 train stations (Department of
Infrastructure and Transport, 2012).