There was a similar grade separation in Geelong road, West Footscray. Again in an already built up area. It’s quite hard to cross the railway there on foot. That’s a location where rail under may have been a better choice.

There is still a shopping centre in Sunshine, so I wonder this is that same shopping centre that was relocated during the works. As long as there is room to relocate, an overpass will still do.

Ballarat Road and Hampshire Road in Sunshine were both 1960s projects, when the area was already built up – the latter overpass required a big chunk of the shopping centre to be demolished.

Looking at the arial photo on the left, you can see that St. Albans wasn’t yet that built up in 1945.
If those level crossings were grade separated before the area was built up, they would have been much cheaper (even in today’s dollars) and much less disuptive. It would have been as simple as shifting the road level above or below the surrounding land and the railway would have stayed at ground level.
Similar grade separations were built at Sunshine station, Ballarat road, also in Sunshine, later at Taylors Road, Delahy, Kings Road, Taylors Lakes and Anderson road, again in Sunshine.

There were also road-over grade separations in areas already built up at the time, such as at West Footscray, Oakleigh and Huntingdale and these gave road overpasses across railways a bad reputation.

I’d cut them a little slack – it took until the 1970s for St Albans to become connected to the rest of Melbourne by suburbia.

The road traffic congestion in the vicinity of station level crossings is caused by the level crossing intersection remaining closed for long intervals; the position of one of the station platforms and its relative position to the level crossing area, forces the intersection to remain closed during the unloading and loading of passengers from train carriages.

Traffic congestion at level crossings is expected to worsen in the future. The need for public transport in Melbourne, particularly the train network, will increase during the next twenty years to new heights. According to a Federal Government new audit report of Melbourne

The delay in the booms rising behind a train is due to a design feature of modern track circuits. Modern track circuits have a built in delay – typically 2 seconds – between the train leaving the track circuit and the track circuit registering ‘clear’. This is a safety feature.

Older track circuits would register ‘clear’ as soon as the train left the track circuit. This can cause serious problems with modern short trains (e.g rail motors like the Vlocitys) which can ‘disappear’ from the track circuit for brief periods of time as they travel along. This could cause boom barriers to momentarily cease operating (and start to rise), or even a signal behind the train to momentarily clear.

The delay built into modern track circuits reduces significantly the likelihood that these problem will occur. A modern short train would have to ‘disappear’ from the track circuit for 2 seconds before problems would occur – which is very unlikely.