Porter Airlines has launched online promotions in response to the Via strike. (CBC)

Canadians stranded by the Via Rail strike have a few options as other transportation companies take steps to accommodate an anticipated increase in demand.

"We have definitely seen an increase in passenger inquiries and bookings," Greyhound spokesperson Abby Wambaugh said.

The bus company uses a flexible scheduling system that allows it to redirect buses to different routes as demand warrants.

Much of Greyhound's sales are done within hours of scheduled departures, which makes gauging demand in advance problematic.

"There's obviously a limit to how many more passengers we can accommodate, but we're certainly more than capable of expanding our capacity," Wambaugh said.

'We have definitely seen an increase'—Greyhound spokesperson Abby Wambaugh

A check of Greyhound's website on Friday afternoon revealed seats were still available on numerous routes in the busy Toronto-Ottawa-Montreal corridor.

Bus operator Coach Canada's ridership is "up dramatically already," company president Jim Devlin said.

"We've expanded our service between Toronto, Kingston and Montreal," Devlin said. "We've added more buses and double-decker buses. We definitely have the capacity to move anyone who requires it."

Hoping to capitalize on stranded passengers, Toronto-based Porter Airlines is offering a 25 per cent discount on all domestic routes for any flights booked before Monday, July 27.

Porter flights to Toronto, Ottawa, Montreal, Quebec City, Thunder Bay and Halifax are all eligible for the discount.

"This is an opportunity for people to keep their summer travel plans without disruption," Porter president Robert Deluce said.

To be eligible for the discount, passengers must enter code VIA25 while booking online or by phone, and travel must take place before Aug. 31.

Canada's largest air carrier, Air Canada, has yet to see any significant spike in demand, but the airline will be matching Porter's sale prices on all competing routes, spokesman Peter Fitzpatrick said.

"Our call centres are reporting normal activity at the moment, but we do have the ability to increase capacity on certain routes should we determine that's necessary," he said.

"And we will match any discounts offered by other airlines on affected routes."

Calgary-based WestJet Airlines Ltd. said it has no plans for now to add any flights.

There is "no significant impact at this point and no plans to add any flights. There is sufficient capacity in our system to accommodate guests whose travel plans may be affected," WestJet spokesman Robert Palmer said.