According to federal government, there were 0.63 deaths per 100 million kilometres travelled in 2010, and 0.44 in 2020.

That's a 30% improvement in actual road safety (nationwide) over the last ten years. I'm not sure what the numbers are for Victoria, but I'm sure it's in the same ballpark (VicRoads publishes "per capita" stats, which is a shitty way to measure road safety).

There's also been a lot of substandard materials used by DoT contractors post Covid, which means that the project supervisors also really have to keep an eye on things as well

However all the good regional supervisors at the DoT have gone into consultancy, leaving their regional offices staffed with a lot of graduates.

I'm also going to say that intersection design is also a bigger factor than road surfaces. Especially as a now banned optical illusion causing intersection style is still rife across the regions. Drivers on the side road think that the intersection is a roundabout. But in fact they need to yield to the main road.

The Chiltern quadruple fatality was caused at one such intersection, and it's quite easy to see how the intersection can be perceived as a roundabout.

We're not gonna have the resources to replace every intersection. However it's almost negligent leaving that style of intersection on the main alternative route into Chiltern.