Through PTV's network development plan, V-line services will in future be diverted via the Upfield Line, to cater for the capacity needs of the Craigieburn Line. I believe that there is a better solution. The Albion East line consists mostly of one standard and one broad gauge line. However, the Broad Gauge line is in a rather poor condition, and has speed restrictions. If both lines are converted to dual gauge for the entire length of the line, then Broad Gauge freight, such as APEX quarry and Tocumwell Goods trains can operate much faster. However, if the Standard Gauge line is duplicated and converted to dual gauge beyond the Albion East Line from Jacana to Craigieburn, then there will be benefits for both Standard and Broad Gauge trains. If you have been to Roxburgh Park, you will know that freight trains wait for hours on the passing loop provided. Although, this could provide even more benefits. The Albion East Line joins the Sunbury line near Albion, which is only one station away from RRL. If a new V-Line only line is created to the city part of RRL, then V-lines to Seymour and Shepparton could be successfully diverted onto this line. This way, commuters travelling by car on near the Upfield Line won't have to wait even longer at level crossings.Little infrastructure should be required to implement this, and then after this, all V-lines will be able to share the benefits of the city RRL lines.
Okay, after reading some comments, I have thought of something else. Although I do not really know much about the capacity of the Bunbury Street Tunnel, if the standard gauge line into the city centre was converted into dual gauge, then broad gauge V-lines could completely avoid RRL, and little infrastructure would be required. Please comment of what you think of this.