布羅爾－單福線
In 2006, a study was completed on the prospects of this line. It recommended upgrading the line to handle larger ART Mark II vehicles, at a cost of $360 million (2006 dollars). Extending the Bloor–Danforth line (either along the current Scarborough RT route, or along a different alignment directly to Scarborough Centre) was not considered cost-effective or justifiable.