As I stated earlier this route is not about getting to the Melbourne CBD but avoiding it. There is a lot of traffic from the eastern/south eastern suburbs that heads north. Often because the distances are relatively short or the receiving and sending areas don't have rail freight services it doesn't make sense to have the 2 transfers with the associated delays, costs and environmental impacts (after all forklifts and cranes use energy too).That was the goal of the project, but Option A doesn't achieve it. Of the 4 routes, it is the only one that will drastically increase traffic into the CBD. The only area of Melbourne that seems to support this route is Eltham and surrounds, and it's so they can drive to the city. It is predicted to move 20,000 passengers from rail to road.
It also reduces congestion on the Burnley Tunnels, Bolte Bridge etc and provides an alternative when there are issues with the tunnels (remember when they were closed for a week around 2007/8 when there was a fatal accident resulting in a fire which damaged the safety systems and road surface.
The backup to the burnley tunnel is also not achieved. The Mullum Mullum tunnels are already at capacity. They cannot function as a backup to Citylink. The interchange at Bulleen it only 2 lanes wide. It would be the narrowest part of the pseudo 'ring road', and will cause a massive bank up of traffic on the Eastern Freeway.
It is also the only route that is almost entirely brownfield construction with no existing easement at all. This means years of massive traffic disruptions. It's the only route that will require regular closures of Greensborough rd - Rosanna rd - Bulleen rd, which is the route that it claims to be 'fixing'.