Metrolinx is drilling into a busy Toronto intersection to build what will become the busiest point on the Ontario Line subway, a 15-station,15.6-kilometre subway line running between Exhibition Place and the Ontario Science Centre.

The monumental task of excavating stations, building bridges, gutting buildings, widening rail corridors, and, of course, tunnelling the line's underground sections, began with preparatory work in 2021 and is set to take several years to realize, currently scheduled to be completed by 2031.

However, work is rapidly progressing on the earliest stages of construction for the Ontario Line's stations, including a significant milestone that was recently surpassed at the site of the line's future Queen Street station.

Metrolinx announced on Thursday that piling work had begun for the new station being constructed deep below the existing Line 1 Queen station.

The first pile is in at the future Ontario Line subway station at Queen! The new station, which will be built below the existing TTC station, is expected to be the busiest connection point along the line. One down, 600 to go! pic.twitter.com/TxszB0NMqe

— Ontario Line (@OntarioLine) June 13, 2024

The start of piling work is an important milestone on the station's path to opening. However, the initial pile driven into the site is just the first of 600 such boreholes that will need to be drilled over the coming months.

This key transfer between the two routes is expected to greatly relieve the pressure placed on the Bloor-Yonge interchange, and become the busiest station on the Ontario Line.

Metrolinx expects 16,600 people will use Queen Station during the busiest travel hour following its projected 2031 completion.