Victoria has underinvested in new transport infrastructure by the equivalent of $60 billion over the past 30 years, compared with the amounts invested in other states by federal and state governments and private firms.

Bureau of Statistics data shows that since 1986, spending on new roads, rail and other transport infrastructure in Victoria by or for governments has been barely half the average amounts invested in other states, as a share of state economic activity.

The train stuck in the City Loop. Credit:Brett Warren

In a week when hundreds of passengers were stranded when a train broke down in the City Loop, and smashes on the West Gate and Bolte bridges caused traffic jams to bank up for several kilometres, that data helps explain why Melbourne's transport system can no longer cope with the city's record population growth.

The Bureau of Statistics reported on Thursday that Victoria accounted for 36 per cent of the nation's population growth in the year to June.