From Mernda or Wyndham Vale, it takes approximately two gallons of gas to get to the CBD and back. Respectively, this results in $15 and $12 in gas costs alone; this averages to $13.50. When taking the car, you also can incur toll charges when getting to the CBD which can range from $3-10 round one way depending on where you live; conservatively you will get $6 in toll charges. On top of this, if you require parking in the CBD, street parking is limited to around 11,000 spots. For each hour you spend in a parking spot on the street, you have to pay $7. With averaging the gas costs and a conservative toll charge, you are at $20 and with adding in one hour of parking you are near $30.
If you decide to use public transportation, the most you will have to pay is $9 with your Myki card for a round trip from either Mernda to Wyndham Vale to the CBD. If you decide to buy a Myki pass, the cheapest pass will allow you to travel to and from the CBD for a whole year for only $5.40 a day. When comparing this cost or even the $9 charge, you are looking at three to five times the difference in cost to the cheapest driving alternative.
By also taking the train into work, you are freeing yourself up for more time to do anything you want as you travel. When driving a car, you must focus on getting to your destination whereas if you take a train, someone else is doing that for you allowing you to catch up on work, read a book, or even relax.
One of the reasons why more people are moving out to live in the suburbs is due to the extremely high cost of living in the CBD, with some houses costing over 1.4 million AUD, compared to the relatively lower 400k to 600k range in the suburbs (shown in the map below). For most individuals and families, this means that it is likely cheaper to live outside the CBD and commute to and from the CBD each day, as that is where a significant number of jobs are located, as seen in the Job Distribution page.
However, due to the lack of public transit options in the suburbs, most will be forced to buy a car just to commute, which not only makes the environment worse with increased emissions, but also worsens the issues with congestion as seen in the Traffic Volume page. Additionally, economic inequality between citizens living in the suburbs and citizens living in the CBD may also increase as the CBD has a much wider variety of public transit options, meaning that a car is not necessary.
With the addition of the MM2 line, as seen in blue, this would provide another option for travel to the CBD which would assist in reducing the environmental concerns and congestion issues with driving. This could also help with reducing the economic inequality, as citizens living in the suburbs would no longer have to buy a car just to get to the CBD.