Wednesday’s announcement of $3.9-billion for a five-year planning phase is the latest step in a long-running debate over whether to green light high-speed rail in Canada

If it does happen, a high-speed rail line could mean a trip between Montreal and Toronto would take less than three hours, far shorter than the current trip on Via Rail or by car — and in some cases quicker than a flight, after taking into account the trip to the airport and passing through security.

The Liberal government launched a six-year, $3.9-billion design and development plan Wednesday that Prime Minister Justin Trudeau says will eventually connect Quebec City and Toronto with a high-speed rail line.