Australia's Office of the National Rail Safety Regulator has approved the autonomous operation of trains at Rio Tinto's business in the west of the country.
The miner said in financial filings it had received regulatory approval for the project, a key step in its bid to haul ore from pit to port completely autonomously by the end of this year.
Once commissioned, the network will be the world's first heavy haul, long distance autonomous rail operation, which is meant to unlock "significant" productivity benefits.
It added that Pilbara shipments guidance for 2018 remained between 330m - 340m tonnes. This is subject to market conditions and any weather constraints.
Following significant delays (initial estimates pegged a 2015 project start), testing was carried out past year using the company's autonomous trains in early 2017 with drivers onboard for monitoring purposes.
It is understood no decision has been made on what Rio Tinto's train workforce will look like in the face of complete automation.
By March, approximately 65% of all train kilometers were completed in autonomous mode with more than 3 million km having now been covered, the company said.
Rio Tinto will soon begin using driverless trains after Australia's rail safety regulator signed off on the mining heavyweight's new system.
The business' iron ore arm operates about 200 trains in the Pilbara that transport ore from 16 mines to four port terminals.