Yonge North subway extension

The Yonge North subway extension (YNSE) is an extension of the eastern branch of the Toronto subway's Line 1 Yonge–University north of Finch station to Richmond Hill in York Region, Ontario. The 8-kilometre (5-mile) extension will add five new stations – three underground and two at surface level – and had an estimated cost of $5.6 billion as of 2021.

The three underground stations will be located on Yonge Street at Steeles Avenue, Clark Avenue, and Royal Orchard Boulevard, respectively. North of Royal Orchard, the line will curve east then turn back north and emerge above ground to run parallel to GO Transit's Richmond Hill line. The two surface-level stations will be situated along the railway corridor. One of these – Bridge station, located underneath adjacent overpasses carrying Highway 7 and Highway 407 – will serve as a key intermodal hub, connecting with York Region Transit (YRT) and GO buses and offering direct access to the existing Langstaff GO Station. Preliminary construction work began in 2023, with the tunnelling contract awarded in 2025.

Originally, a 7.4-kilometre (4.6 mi) extension was conceived with six fully underground stations: Cummer/Drewry, Steeles, Clark, Royal Orchard, Langstaff/Longbridge, and Richmond Hill Centre. While first priced at $5.6 billion in 2017, the cost for this fully underground version had increased to $9.3 billion by 2021, necessitating the reduction in scope that led to the five-station plan.

Expected to take a decade to complete, the YNSE aims to reduce traffic congestion by eliminating an estimated 2,500 daily bus trips along its corridor. It is forecast to serve 94,000 daily riders and, by 2031, carry 58 million annual passengers. York Region anticipates that the extension will generate 31,000 jobs.