Is not CBTC being installed to sort out the unacceptable variations to TT?
Since the TT for that stretch is 26 minutes for the 20km, precisely how much is the "large amount" to be saved by some exclusive tracks??? Lets be generous and say 10 minutes. Really !!! Time through the section extends out to 32+ minutes during peak which equates to an average speed of 36.39km/h to travel the 19.408 kilometers. That speed is more what you'd find on a tourist railway than a modern mainline. Even out of peak at 26 minutes the average speed is just 44.78km/h. No matter which way you spin it its appallingly slow and its beyond me how anyone can find that acceptable.
The question remains. How much time could realistically be saved, and does that justify the enormous cost of quad tracks ?
45kph sounds typical Metro. Suppose vline could always terminate at the boundary if that is so offensive.
CBTC will just squeeze maximum TPH out of the line by reducing the headways. Currently Fixed Block, going to moving block. However, this will not be installed in the V/line fleet so there will still be line side signalling and traditional Fixed Blocks that the HCMTS will have to work around.
Let's see how good my maths is.
The current South Line is a mix of class 2 (130Km/h), 2U (115km/h) and 1 (160km/h). Braking distance at 160km/h for a Vlo is 550m.
The current morning express from Traralgon (0519) to the Pakenham MTM Boundary takes 61 minutes. At a distance of 98km gives an average speed of just 96km/h. If the average speed was increased to 130Km/h this reduces the average time to 45 minutes. If that was pushed to 150Km/h (pushing it with braking distance for the 5 stations) travel time is reduced to 39 minutes.
This pushes the total travel time closer to 90 minutes as opposed to the 120 it currently is.
Pakenham to Dandenong is 26km. There is plenty of space to build a dedicated track pair for V/Line through to Dandenong. At 130km/h this reduces the running time from 22 minutes to 11.
With a decent two tier service (local & express), track upgrades and easing of a few curves you can shave almost 30 minutes of the running time with out the need to spend billions on acquisitions. Bringing the whole line up to Class 1 and a dedicated track to Dandenong would cost about the same, but money well spent.
Speed is only half the issue, reliability is the biggest one. Most can put up with a slightly longer journey if they know day in day the train will arrive/depart on time. Cancellations and delays are what put people off.
Spare a thought for the poor folk out at Bairnsdale, 90 minutes to Traralgon gives them an average speed of 77km/h. Class two track would slash that to 53 Minutes.