A master plan to extend the downtown PATH walkway is afoot, with a vision to link the subterranean pedestrian system south to the waterfront and north to Ryerson University.
Further west, hospitals on University Avenue will also be connected, according to the draft scheme.
But in addition to the expansion ambitions, city planners also want to revamp existing sections of the climate-controlled tunnels that snake along the PATH's 28 kilometres of shopping arcades.
Michel Trocmé, a planner with Urban Strategies Inc., is helping the city develop its guiding vision for how the PATH should develop in the future.
"We need more daylight, more skylights, more connections to the street level," he said.
"There's a population the size of Peterborough, believe it or not, that works here on a daily basis."
The city estimates that more than 100,000 commuters use the system daily.
The objective of the master plan is to set overall design and building standards for future development of a maze of corridors that have been changing in a patchwork fashion.
With more residents moving south of the city's financial hub, city planners noted the Lakeshore should also join the PATH system.
That might be accomplished via a series of above-ground bridge linkages, such as a proposed connection joining the Air Canada Centre to a new office complex near Harbour and York streets.
A 2015 timeline has reportedly been set to build those links to the new WaterPark Place III complex.
Still, this is assuming city council will approve of expanding what Guinness World Records has recognized as the world's largest underground shopping complex. Councillors are expected to vote on the PATH master plan next year.