A major road through Southbank will have the number of lanes for cars cut in half and the space for vehicles replaced with parkland, under a long-promised Melbourne City Council plan that begins construction on Monday.

Southbank Boulevard will become the “green spine” of the Melbourne Arts Precinct, with the road to be converted into what acting Lord Mayor Arron Wood said was “the most significant linear park in Melbourne".

The road will be shut between St Kilda Road and Sturt Street from Monday, July 16, with the project due for completion in August next year.

It is the latest under-utilised stretch of inner-city road to be replaced by park, with two separate streets in North Melbourne being turned into green space in recent years.