Though the benefits to this point have focused on the first few stages of construction between Don Mills and Eglinton and Dundas West Station, the benefits would increase even further when evaluating the logical expansion of the line both North from Don Mills and Eglinton, and Northwest from Dundas West Station.
An extension north on Don Mills Rd. to Sheppard creates an important connection to the Sheppard subway, allowing passengers to choose between Yonge and the DRL as a way of getting downtown. With pockets of density at Don Mills and Lawrence as well as Don Mills and Sheppard, the line could hold its own to justify the extension to connect with the Sheppard line. If the Sheppard subway does not get extended eastwards as a result of the Transit City Sheppard LRT, the Downtown Relief Line would allow passengers from Sheppard to get downtown with one transfer, rather than transferring to the Sheppard subway to continue their journey to Yonge, then again transferring to the Yonge train.
GO Georgetown Corridor. Looking at the TTC’s Rapid Transit Expansion Study, the area around the Weston corridor shares the distinction with the Waterfront West area, and Don Mills (served by the early segments of the DRL) of being the only parts of Toronto that have a projected density of higher than 100 persons + jobs / hectare (ppj/ha)119. The density around this area clearly supports a subway by the TTC’s own definition, and the only reason this would be a later extension is due to financial reasons and the pressing needs of the earlier stages to be constructed. Still, this is an extension that would be easily justified just based on density alone. If you consider the cost savings due to it being able to be constructed above ground if provisions are made for it during the reconstruction of the Georgetown corridor, a subway extension serving this area would be incredibly cost effective at generating a substantial ridership. A subway line to the northwest of the city can substantially decrease travel times for those in Northern Etobicoke, who currently see incredibly long journeys to downtown.
Furthermore, the western extension can be run to Pearson Airport along one of many different possible routes, of which I prefer Dixon Rd. due to the high density apartments on Dixon between Islington and Kipling, the width of Dixon allowing for cut-and-cover construction while still keeping the road open at a temporarily lower capacity, and due to it being a direct route to the airport without having to curve back on itself, allowing stops at the Toronto Congress Centre at Highway 27 where a quick shuttle can run between the station and Woodbine Racetrack, and a large concentration of aiport hotels at Dixon and Carlingview. This would provide the rapid transit to the airport that the city sorely lacks, while the Eglinton LRT can provide slight relief until this is constructed.
The Downtown Relief Line has extensions that can be well justified even beyond the initial construction of the line, forming a cohesive backbone to a transit system for years to come.
From top to bottom: