MILLIONS of Australians living on the outskirts of major cities — including about 500,000 in Perth — are being left behind by poor access to public transport.

According to an Infrastructure Australia report to be released today, the lack of access is forcing people into cars — with vehicle operating costs leaving less money for other household expenses.

It also meant they had less access to jobs, education and “other opportunities to get ahead”.

The report said the cost of public transport was generally more expensive in lower density, outer-suburban areas.

But new technology and delivery models — including on-demand buses — could offer a solution by increasing the flexibility and reach of the network.

“This report makes a clear case for governments to consider new models such as on-demand buses and ride-sharing to complement more traditional modes like bus and rail,” Infrastructure Australia’s policy and research executive director Peter Colacino said.

The report found half of all residents in Perth’s outer suburbs — extending out from Sorrento, Thornlie and Anketell — were not within walking distance of a frequent public transport service.

And one in five outer-Perth residents travelled more than 30km to work, compared with only 2 per cent in the inner city.

Mr Colacino said State governments needed to improve the efficiency of existing transport networks and consider new models to service communities in the growing outer suburbs.

He said the research showed outer city residents had poor service frequencies and longer travel times than inner-city residents.

“We also want governments and transport operators to do more to encourage people to transfer between public transport services, which helps to increase the flexibility and reach of the network,” Mr Colacino said.

“This includes investing in well-designed interchanges, extending integrated ticketing systems to new modes and introducing fare incentives that actively encourage people to transfer between modes to get to their destination.”

The report found that across all cities, car ownership was higher in the outer suburbs.

Sixty-three per cent of homes in the outer suburbs owned multiple vehicles, compared with 35 per cent of homes in the inner city.