The bridge, which arches over Mullet Creek, provides southern access to the West Dapto subdivisions via Fairwater Drive.

The Wollongong City Council work also includes a roundabout, bus bay, drop-off zone and turning circle next to Dapto High School, which is nearing completion.

Lord Mayor Gordon Bradbery said the completed section of Cleveland Road was wider, safer and more accessible, and also less likely to flood during heavy rain.

The Cleveland Road bridge completion means the next stage of the nearby Shone Avenue upgrade - a $5.3 million project signed off in April - can now go ahead.

From Monday, Shone Avenue will be reduced to one lane and will be fully closed from September to allow the construction of a two-lane bridge and channel works.

Council staff said the closure was cheaper and less risky than allowing the road to stay open during construction.

"We understand this closure will cause some inconvenience however we ask the community to please be patient because it really is a case of relatively short term pain for long term gain,” Cr Bradbery said.

He also said the upgraded West Dapto Road and Princes Highway intersection, near Kembla Grange, was due to reopen by the end of July.

"The construction of a four-way intersection with traffic signals and a left turn lane from West Dapto Road will have a big impact on safety and road capacity which is important given the growing volume of traffic in the area," he said.

All three road upgrades are part of the council's $72 million West Dapto Access Strategy, which also includes a $45 million road to link the Princes Highway and Fowlers Road intersection to West Dapto, with a bridge spanning the rail line and Mullet Creek.

The Fowlers Road link received $22.5 million from the NSW government's $100 million port privatisation fund but the other half of the project remains unfunded.

Councillors awarded a $1 million contract for Cardno Engineering to design the road in March.