The City of Toronto has two “railways to nowhere”: the Sheppard subway and the Richmond Hill GO train.
The Sheppard Subway
The Sheppard subway is 5.5 km long, has five stations, and connects to only one other rail line, the Yonge line. By comparison, the Yonge-University subway will soon be 38.8 km long (when the Vaughn extension begins operation), will have 38 stations, and will connect to many other rail lines, including the Bloor-Danforth subway, the Sheppard subway, 7 GO train lines (all at Union), and eventually also the Eglinton Crosstown.
The Bloor-Danforth subway is 26.2 km long, has 31 stations, and has connections with other rail lines at stations like Dundas West (the Union-Pearson Express train and the Kitchener GO train), Main Street (the Stoufville GO train and Lakeshore East GO train) and Kennedy (the Scarborough RT*, Stoufville GO train, Eglinton, and, if the City’s current transit plans are realized, the Scarborough subway tunnel).
The Richmond Hill GO Train
Before the start of this year, the Richmond Hill GO train line was 34 km long and had five stations, three of which were located within the City of Toronto. With an extension to a new station, Gormley Station, having been opened in 2017, the line is now 42 km long, with six stations—but still only three in the City of Toronto. In contrast, the other six GO lines are between 50-103 km long (for an average of 69.6), have between 9-13 stations (for an average of 11.2), and have between 2-6 stations within Toronto (an average of 4).
Read more: Toronto Crow’s Advantage (…apologies for some of the pictures being blurry and links being broken, I’ll try to fix them soon)
Future Economics 
