Hopefully to settle the debate/add some non-fantasy speculation about a northern Canada Line extension, this was analysed in some depth in the 2020 Burrard Inlet Rapid Transit study.
https://news.gov.bc.ca/files/9-15_Burrard_Inlet_study.pdf#page=29
Option 1A explored a spur off of the Canada Line after Yaletown-Roundhouse and was deemed unfeasible.
Option 2A explored
lowering Vancouver City Centre and Waterfront in order to tunnel beneath the harbour. This was not considered unfeasible, but only basic analysis was done.
Threaded Mode