Road closures, lane reductions and major construction will begin next month as part of the Metro Tunnel project.
Extended lane reductions on St Kilda Road and the complete closure of Grattan Street will enable work to begin on new underground stations being built as part of the $11 billion project.
St Kilda Road will be reduced to one lane in both directions for around 800 metres between Kings Way/Toorak Road West and Dorcas Street for up to four years. Tram access along St Kilda Road will mostly operate as normal over this period, while pedestrian and cycling access will be maintained.
Grattan Street will close in both directions for around 300 metres from Royal Parade to Leicester Street for up to five years. Pedestrian access will be maintained through Grattan Street with some diversions for cyclists.
Motorists should allow up to 15 minutes extra travel time if they travel along this stretch of St Kilda Road or through Parkville.
Alternative routes for St Kilda Road include Kings Way, Queens Road, Ferrars Street and Beaconsfield Parade. Grattan Street alternatives include Queensberry Street, Alexandra Parade and Cemetery Road/College Crescent.
Additional changes will take place in February and April around the Anzac Station site on St Kilda Road.
Buses will replace trams on a section of Route 58 in February while a new tram stop is built on Park Street in South Melbourne. During the April school holidays, buses will replace all trams along a section of St Kilda Rd as tram tracks and traffic lanes are reconfigured.
More than $25 million of road and traffic upgrades are being delivered across Melbourne to keep the city moving while the Metro Tunnel is built. This includes creating more traffic lanes on alternative routes, widening and re-marking roads and reprogramming more than 100 traffic lights at key intersections.
Some changes to local bus routes and timetables will also be necessary to carry out these works.