“The future is now,” they said in Canada in 1975. They should have known better. Prime minister Pierre Trudeau had just opened Montreal’s new international airport. The city was booming and needed a designer terminal to prove it was up there with Paris, London and New York. So they built one. In fact they built what was then the world’s largest. At a cost of pound;225 million, Mirabel airport was made beautifully modern and comfortably vast in the hope that its seven million visitors would never have to rub suitcases.

It was the airport of the year 2000, they said. But not, it seems, of 2004.

Mirabel never processed even half the predicted number of visitors and now a mere 800,000 drift past the check-in desks annually. Next year even they will disappear and the pride of 1975 will become a cargo terminal.

So what went wrong? In the late 1960s the city’s small Dorval airport could not cope. Montreal was a key refuelling stop. Planes could not make it from Europe to the west coast of the States without a little top-up and Dorval was the place to do it. However, the government failed to foresee that planes - and their fuel tanks - would get bigger. A heck of a lot still fly over Montreal, they just no longer land.

There were other problems, too. First, there was politics. The brave citizens of Quebec elected a separatist government a year after Mirabel opened. Many not-so-brave businesses then elected to flee the state’s capital city.

Then there was transport. Dorval is only 15 minutes from the city centre, but Mirabel is 45 miles away and - surprise, surprise - the planned road and rail links were never built. Passengers who had to transfer between the airports could sit for two hours in rush-hour traffic. Their plight was ammunition to the experts who argued that a city is best served by just one big airport or “hub”.

They seem to be about to get their way. Dorval airport, neglected for decades, is now getting a pound;350 million make-over. Meanwhile at Mirabel, the trolleys stand empty, waiting for all those who will never make it to Arrivals.