The number of travellers using Billy Bishop Toronto City Airport rose sharply in 2011, thanks to more flights operated by Porter Airlines and the introduction of service by Air Canada.

More than 1.5 million travellers used the island airport just south of Toronto's downtown core in the past 12 months, up 37 per cent from 2010 and double the number of passengers in 2009, the Toronto Port Authority estimates.

The authority, which owns and operates the airport, is expecting that number to climb significantly again in 2012, to two million, said spokesperson Suzanna Birchwood.

Air Canada launched operations at Billy Bishop last May and now operates 15 flights a day from the island airport to Montreal, said Birchwood.

Five-year-old Porter, based at Billy Bishop, introduced service to Windsor, Sault Ste. Marie and Burlington, Vt., in 2011, and increased its number of flights to other destinations, including Ottawa, Sudbury, Thunder Bay, Mont Tremblant, Que., and Boston.

It is adding Timmins to its list of destinations on Jan. 16, and either Philadelphia or Washington, D.C., likely in the spring, said Porter spokesperson Brad Cicero.

Port authority CEO Geoff Wilson said the growth in traffic shows that Torontonians and visitors consider the airport a great asset for the city.

"Together with our airlines, Porter and Air Canada, we have made great strides in meeting customer demands for a quality travel experience," Wilson said.

The port authority plans to begin work on a pedestrian tunnel to the airport terminal in spring 2012 to supplement the current ferry service across a narrow channel.

For comparison's sake, Toronto's Pearson International Airport, on the city's outskirts, handled 31.8 million passengers in 2010.