Infrastructure Victoria has issued a scathing report on the state's regional roads and rail freight networks, saying neither has clear long-term funding programs for maintenance and upgrades.
It's called on the state government to set aside $70 million a year, for the next 30 years, to maximise efficient maintenance of the Victorian rail freight network.
"Ultimately, when the government does more detailed business cases, they may land a slightly different number," Infrastructure Victoria Research and Economics director Llewellyn Reynders said.
The figure was based on longer, multi-year projects.
"That was our strategic estimate of the kind of dollars we were looking at," he said.
Infrastructure Victoria also called on the government to dedicate a 10-year funding program to regional road maintenance and upgrades.
Reviews had criticised Victoria's road maintenance strategy and prioritisation processes.
"Despite significant one-off funding allocations, particularly for regional roads, neither network has clear long-term funding for maintenance and upgrades, making strategic and efficient management difficult," the report found.
Mr Reyners said it had been a problem that had occurred, over many decades.
"It's not limited to Victorian governments - it's something we see, across the nation," he said.
Infrastructure Victoria found rail's share of freight was "stagnant or in decline, meaning the freight rail network is underused, especially on freight-only regional lines.
"Compared with the regional passenger network, rail freight has significantly more assets in average, poor, or end-of-life condition.
"A badly maintained regional rail freight network has lower performance and reliability, reduces asset longevity, and increases catastrophic failure risk."
Efficiency was hampered by different rail gauges, axle load restrictions, permanent and temporary speed restrictions and maintenance backlogs.
The state government has said it is spending hundreds of millions of dollars on maintaining and upgrading the network, replacing sleepers and delivering other improvements to improve speeds, reliability and increase axle loads.
This includes the replacement of nearly 39,000 sleepers on the Rainbow to Dimboola line and other upgrades including on the Maryvale and Murtoa to Hopetoun.
The $4 billion Regional Rail Revival program was also upgrading regional passenger rail lines, which will support rail freight.
Works to upgrade regional rail lines include new passing loops, upgraded signalling and stabling and level crossing upgrades to make crossings safer for trains and motorists.
Infrastructure Victoria said the most effective and efficient way to improve the rail freight network was to have a long-term funding certainty that underpinned the program.
The periodic regional freight rail maintenance program should be informed by a "publicly available network development and asset management plan".
The government should then use the plan to determine the feasibility of a five-year major regional freight upgrade.
The report also found an increasing proportion of the regional road network was in very poor condition, presenting a growing risk to public safety and increasing the costs of travel through increased fuel use, vehicle maintenance and travel times.
Current annual maintenance funding was inconsistent, meaning it was often left until it was most expensive, which ultimately inflated costs.
Within the next two years, it called for the government to specify "clear levels of service', for each type of regional road and bridge.
"Following this, (it should) dedicate a 10-year program to sustainably fund Victorian government regional road and bridge maintenance and upgrades to meet these service levels," the report said.
"Funding should be prioritised based on improving safety, decreasing vehicle emissions, and lifting productivity.
"After specifying road service levels, funding should be allocated to priority maintenance and upgrades, determined by desired safety, vehicle emissions, productivity outcomes, and existing road condition.
"Unpredictable road upgrade and maintenance funding hinders road managers' ability to prioritise investment across the network from year to year, impedes good road network planning."
The report said the government should provide a transparent framework that defined the level of service, or desired condition, of each type of regional road and bridge in a hierarchy based on defined criteria.
"Not every road needs to be maintained at the same standard but should be maintained to meet its intended purpose.
"The level of service could define the desired speed, volume, safety and types of vehicles the road is intended to carry."
A state government spokesperson said unprecedented investment in infrastructure was being delivered across the state, with billions of dollars going to maintaining and upgrading regional road and rail freight networks.
"On top of the unprecedented investment in rail freight, Victoria is also establishing a long-term plan for the regional freight network taking into account the future needs of the network to 2050," the spokesperson said.
"Detailed planning and modelling is used to determine which roads are prioritised for investment based on data, field inspections and expert knowledge of our road network."