This allowed the tracks to pass underneath nearby railway lines without disturbing them during construction.

To the west, the tracks follow a short "cut and cover" tunnel before emerging outside at the Dorval Portal.

Nearby landmarks include The Crossways residential and retail complex, Bishop Marrocco/Thomas Merton Catholic Secondary School, The Lithuanian House banquet hall, Roncesvalles and The Junction neighbourhoods.

Dundas West station opened in 1966 as a part of the initial segment of the Bloor–Danforth line between Keele and Woodbine.

Customers transferring from the TTC to GO/UPX need to walk 500 metres (1,600 ft) east along city streets from the only station entrance at the west end of the subway platforms.

The work includes:[8] Metrolinx began proceedings to expropriate necessary properties for a pedestrian tunnel in September 2017.