Another good way to avoid any accident of serious nature is to use bike paths. The reason I say this is because while riding on bike paths, I've been seeing a number of near accidents where the cyclists wouldn't even have a clue how it happened until it's too late.
For example, I saw a cyclist riding on the road near South Melbourne Beach the other evening while I was on the bike path. On his left were parked cars and right behind him a truck was trying to overtake the cyclist by moving to the right lane. Problem - there was ANOTHER truck on the right hand side which almost blocked the first truck from shifting lane. The first truck accelerated and barely sneaked through to the right lane (with the RHS truck braking and honking). All these happened behind the cyclist and he wasn't aware of any of that, let alone reacting to it.
Riding on bike paths can prevent these sorts of things from happening. This is especially important if you are training because accident can really muck up your plan. Of course, you still run the risk of crashing into something but at least you know it's coming.
Also, I've tested the bayside route from Port Melbourne to Mordialloc using either road or bike path (bike path terminates somewhere around Mentone). Both yield similar time for me but you may get faster results on the road because the chance of drafting behind other riders is higher. Bike paths have more twists and turns but you don't really have to stop for traffic lights.
At the end it's your personal preference but when I train solo I almost always take as much bike paths as possible, especially after I crashed on Nepean Highway and had to scramble onto the curb for fear of being hit from behind.