More than 42,000 cubic metres of soil - the equivalent of about 20 Olympic-sized swimming pools - have been dug out of the site where Perth's new underground busport will be built.
The excavation project, which sits alongside the city's underground rail tunnel, is 70 per cent finished. Another 10,000cum of soil is to be removed.
But even getting this far has been a major engineering feat.
The underground busport - which will replace the demolished Wellington Street bus station - could not just be dug out because of the rail tunnel and high water table.
Ninety-two pylons had to be driven 40m into the ground and the thick concrete walls and ceiling had to be poured and laid before the soil could be removed.
Transport Minister Dean Nalder said the $209 million busport was on track to open by the middle of next year.
"The Perth Busport will cater for demand for at least the next 30 years," Mr Nalder said. "By 2031, there will be 38,500 passenger movements at the busport.
"At peak times, it will be used by more than 200 buses an hour - that represents hundreds, if not thousands, of cars off our roads and more choice for passengers."
A key feature of the busport will be its "dynamic bus allocation" system, which is similar to airport gates. It monitors buses as they approach the station and allocates them a stopping stand.
The information is communicated to patrons in a glass- enclosed waiting lounge with seating for 160 people. The technology has been a success in the Christchurch Bus Exchange in New Zealand and Kamppi Terminal in Helsinki, Finland.
Mr Nalder said the system would allow the busport to handle 50 per cent more buses than the old Wellington Street station.
"By the time the busport opens, a project to install real-time tracking software in every Transperth bus will be complete, allowing passengers to see just when their service will arrive," he said.