A major part of the $5.2 billion Perth CityLink project has been brought to completion within budget and six months ahead of schedule.

With a pedestrian underpass now open to the public, the final stage of the rail component of the Perth City Link project is complete.

Set to reconnect the Perth CBD with Northbridge for the first time in more than 100 years, the broader CityLink Project represents a 13.5-hectare urban renewal development running east-west through an area in the city centre bounded by the Mitchell Freeway, Roe Street, Wellington Street and the Horseshoe Bridge which is expected to deliver improved connectivity and access to transport. It will also see added residential, commercial and retail floor space and open public space and, together with the $2.6 billion Elizabeth Quay waterfront project, a 40-hectare Riverside project on the city’s eastern gateway and the new Perth Stadium, is part of the government’s plan to transform the city.

Performed by John Holland and GHD, work on the rail aspect of the project started in 2011 and involved creation of a 600-metre underground tunnel in order to sink the Fremantle Line from William to Lake/King Streets.

This will be followed by the sinking of the Wellington Street Bus Station.

The new underpass, which formed the last part of the rail sinking stage of the project, is expected to be used by 9,000 commuters daily to connect from Perth Underground to Perth Station. Its construction involved more than 7,500 cubic metres of concrete.

Western Australian Transport Minister Troy Buswell said the sinking was a complex project and congratulated all involved.

“This is a very significant day for the people of Perth because the State Government has achieved something that has been talked about for decades,” he said.

The completion of the first stage of the project follows the awarding of preferred contactor states to a joint venture between Leighton Properties and Mirvac for the development of 5.1 hectares of prime CBD land as part of the project.

Once complete, that development will house 3,000 people in 1,200 apartments and accommodate 13,500 workers in approximately 150,000 square kilometres of retail and office space.