Building elevated rail to remove level crossings is a superior outcome for Melbourne to digging trenches or building road overpasses, a study has found.

The Benefits of Level Crossing Removals, a joint Melbourne University-RMIT study that looks back at more than a century of level crossing removals in Melbourne, concluded that elevated rail has produced more benefit for Melbourne transport users than other removal techniques.

The report, released on Wednesday, is an attempt to inform the debate over how to remove the city's 170 remaining level crossings, and a rebuttal of arguments that the Andrews government's plan to elevate nine kilometres of the Dandenong rail corridor will be a community disaster.

It looks at grade separation projects that have succeeded and failed since the 1850s. Four options have been used to separate road and rail in Melbourne – elevate the rail, elevate the road, sink the rail, sink the road.