How quick would a train go from, say, Perth to Mandurah non-stop? Because I was thinking during peak times, some of the trains going against the grain could just go express to the terminus to have a quicker throughput and to get passengers into the city quicker.
For example, in the morning, trains come down the Joondalup line as usual, they stop at Esplanade station, then go express all the way to Mandurah station, then go up the Mandurah line as usual. This way, there would be more trains per hour, so there should be less waiting and less cramming. And because there are very few passengers going against peak flow, it wouldn't be a problem.
Of course, not all trains would be express (there are still people that need them), but maybe 1 in 2 or 3 trains would stop at the stations.
And this probably wouldn't work on the Midland and Fremantle lines as I would have thought there would be too many passengers going to Fremantle/Midland and stops along the way. And the Joondalup line trains might stop at Joondalup too. And the Armadale/Thornlie line might need some reconsidering with issues with transfers at Cannington between the 2 lines.
So yeah, I don't know how beneficial my idea would be, and how much time would be saved, but I was thinking it could theoretically help a lot, and because the trains repeat the journey more regularly, there wouldn't need to be as many trains (ie. wouldn't need to buy as many more).